The Node.js Runtime v8 options list

All the possible options you can use when you start a Node.js program

Node.js can be invoked with an incredibly various set of options.

Most of those options are used to configure the v8 engine behavior.

Some of the options here are disabled by default, as you can see in the Default column. You can enable them by running node and passing the flag, for example node --experimental-extras.

If an option is enabled by default, you can disable it by prepending --no- to the flag name, for example node --no-harmony-shipping.

Some can be used to optimize performance, like --optimize-for-size, --max_old_space_size and --gc_interval, like Heroku suggests.

Some others are used to enable or disable specific features. I use them often to try out new proposed JavaScript features that have been implemented in beta. Like --harmony-public-fields.

Note: options names allow words to be separated by both dashes (-) or underscores (_), or a mix of those. On tutorials you’ll find a mix of both, to it can be confusing. There is no difference.

I got the following list by running the command node --v8-options, and it’s relative to Node.js 11.9.0, the latest Node.js version at the time of writing.

Option	Description	Type	Default
`--experimental-extras`	enable code compiled in via v8_experimental_extra_library_files	bool	false
`--use-strict`	enforce strict mode	bool	false
`--es-staging`	enable test-worthy harmony features	for internal use only	bool
`--harmony`	enable all completed harmony features	bool	false
`--harmony-shipping`	enable all shipped harmony features	bool	true
`--harmony-do-expressions`	enable “harmony do-expressions”	in progress	bool
`--harmony-class-fields`	enable “harmony fields in class literals”	in progress	bool
`--harmony-static-fields`	enable “harmony static fields in class literals”	in progress	bool
`--harmony-await-optimization`	enable “harmony await taking 1 tick”	in progress	bool
`--harmony-locale`	enable “Intl.Locale”	in progress	bool
`--harmony-intl-list-format`	enable “Intl.ListFormat”	in progress	bool
`--harmony-intl-relative-time-format`	enable “Intl.RelativeTimeFormat”	in progress	bool
`--harmony-public-fields`	enable “harmony public fields in class literals”	bool	false
`--harmony-private-fields`	enable “harmony private fields in class literals”	bool	false
`--harmony-numeric-separator`	enable “harmony numeric separator between digits”	bool	false
`--harmony-string-matchall`	enable “harmony String.prototype.matchAll”	bool	false
`--harmony-global`	enable “harmony global”	bool	false
`--harmony-string-trimming`	enable “harmony String.prototype.trim{Start,End}“	bool	true
`--harmony-sharedarraybuffer`	enable “harmony sharedarraybuffer”	bool	true
`--harmony-function-tostring`	enable “harmony Function.prototype.toString”	bool	true
`--harmony-import-meta`	enable “harmony import.meta property”	bool	true
`--harmony-bigint`	enable “harmony arbitrary precision integers”	bool	true
`--harmony-dynamic-import`	enable “harmony dynamic import”	bool	true
`--harmony-array-prototype-values`	enable “harmony Array.prototype.values”	bool	true
`--harmony-array-flat`	enable “harmony Array.prototype.{flat,flatMap}“	bool	true
`--harmony-symbol-description`	enable “harmony Symbol.prototype.description”	bool	true
`--icu-timezone-data`	get information about timezones from ICU	bool	true
`--future`	Implies all staged features that we want to ship in the not-too-far future	bool	false
`--allocation-site-pretenuring`	pretenure with allocation sites	bool	true
`--page-promotion`	promote pages based on utilization	bool	true
`--page-promotion-threshold`	min percentage of live bytes on a page to enable fast evacuation	int	70
`--trace-pretenuring`	trace pretenuring decisions of HAllocate instructions	bool	false
`--trace-pretenuring-statistics`	trace allocation site pretenuring statistics	bool	false
`--track-fields`	track fields with only smi values	bool	true
`--track-double-fields`	track fields with double values	bool	true
`--track-heap-object-fields`	track fields with heap values	bool	true
`--track-computed-fields`	track computed boilerplate fields	bool	true
`--track-field-types`	track field types	bool	true
`--trace-block-coverage`	trace collected block coverage information	bool	false
`--feedback-normalization`	feed back normalization to constructors	bool	false
`--optimize-for-size`	Enables optimizations which favor memory size over execution speed	bool	false
`--enable-one-shot-optimization`	Enable size optimizations for the code that will only be executed once	bool	true
`--unbox-double-arrays`	automatically unbox arrays of doubles	bool	true
`--interrupt-budget`	interrupt budget which should be used for the profiler counter	int	147456
`--ignition-elide-noneffectful-bytecodes`	elide bytecodes which won’t have any external effect	bool	true
`--ignition-reo`	use ignition register equivalence optimizer	bool	true
`--ignition-filter-expression-positions`	filter expression positions before the bytecode pipeline	bool	true
`--ignition-share-named-property-feedback`	share feedback slots when loading the same named property from the same object	bool	true
`--print-bytecode`	print bytecode generated by ignition interpreter	bool	false
`--print-bytecode-filter`	filter for selecting which functions to print bytecode	string	*
`--trace-ignition-codegen`	trace the codegen of ignition interpreter bytecode handlers	bool	false
`--trace-ignition-dispatches`	traces the dispatches to bytecode handlers by the ignition interpreter	bool	false
`--trace-ignition-dispatches-output-file`	the file to which the bytecode handler dispatch table is written	by default, the table is not written to a file	string
`--fast-math`	faster	but maybe less accurate math functions	bool
`--trace-track-allocation-sites`	trace the tracking of allocation sites	bool	false
`--trace-migration`	trace object migration	bool	false
`--trace-generalization`	trace map generalization	bool	false
`--concurrent-recompilation`	optimizing hot functions asynchronously on a separate thread	bool	true
`--trace-concurrent-recompilation`	track concurrent recompilation	bool	false
`--concurrent-recompilation-queue-length`	the length of the concurrent compilation queue	int	8
`--concurrent-recompilation-delay`	artificial compilation delay in ms	int	0
`--block-concurrent-recompilation`	block queued jobs until released	bool	false
`--concurrent-compiler-frontend`	run optimizing compiler’s frontend phases on a separate thread	bool	false
`--strict-heap-broker`	fail on incomplete serialization	bool	false
`--trace-heap-broker`	trace the heap broker	bool	false
`--stress-runs`	number of stress runs	int	0
`--deopt-every-n-times`	deoptimize every n times a deopt point is passed	int	0
`--print-deopt-stress`	print number of possible deopt points	bool	false
`--turbo-sp-frame-access`	use stack pointer-relative access to frame wherever possible	bool	false
`--turbo-preprocess-ranges`	run pre-register allocation heuristics	bool	true
`--turbo-filter`	optimization filter for TurboFan compiler	string	*
`--trace-turbo`	trace generated TurboFan IR	bool	false
`--trace-turbo-path`	directory to dump generated TurboFan IR to	string	nullptr
`--trace-turbo-filter`	filter for tracing turbofan compilation	string	*
`--trace-turbo-graph`	trace generated TurboFan graphs	bool	false
`--trace-turbo-scheduled`	trace TurboFan IR with schedule	bool	false
`--trace-turbo-cfg-file`	trace turbo cfg graph	for C1 visualizer to a given file name	string
`--trace-turbo-types`	trace TurboFan’s types	bool	true
`--trace-turbo-scheduler`	trace TurboFan’s scheduler	bool	false
`--trace-turbo-reduction`	trace TurboFan’s various reducers	bool	false
`--trace-turbo-trimming`	trace TurboFan’s graph trimmer	bool	false
`--trace-turbo-jt`	trace TurboFan’s jump threading	bool	false
`--trace-turbo-ceq`	trace TurboFan’s control equivalence	bool	false
`--trace-turbo-loop`	trace TurboFan’s loop optimizations	bool	false
`--trace-alloc`	trace register allocator	bool	false
`--trace-all-uses`	trace all use positions	bool	false
`--trace-representation`	trace representation types	bool	false
`--turbo-verify`	verify TurboFan graphs at each phase	bool	false
`--turbo-verify-machine-graph`	verify TurboFan machine graph before instruction selection	string	nullptr
`--trace-verify-csa`	trace code stubs verification	bool	false
`--csa-trap-on-node`	trigger break point when a node with given id is created in given stub. The format is: StubName,NodeId	string	nullptr
`--turbo-stats`	print TurboFan statistics	bool	false
`--turbo-stats-nvp`	print TurboFan statistics in machine-readable format	bool	false
`--turbo-stats-wasm`	print TurboFan statistics of wasm compilations	bool	false
`--turbo-splitting`	split nodes during scheduling in TurboFan	bool	true
`--function-context-specialization`	enable function context specialization in TurboFan	bool	false
`--turbo-inlining`	enable inlining in TurboFan	bool	true
`--max-inlined-bytecode-size`	maximum size of bytecode for a single inlining	int	500
`--max-inlined-bytecode-size-cumulative`	maximum cumulative size of bytecode considered for inlining	int	1000
`--max-inlined-bytecode-size-absolute`	maximum cumulative size of bytecode considered for inlining	int	5000
`--reserve-inline-budget-scale-factor`	maximum cumulative size of bytecode considered for inlining	float	1.2
`--max-inlined-bytecode-size-small`	maximum size of bytecode considered for small function inlining	int	30
`--min-inlining-frequency`	minimum frequency for inlining	float	0.15
`--polymorphic-inlining`	polymorphic inlining	bool	true
`--stress-inline`	set high thresholds for inlining to inline as much as possible	bool	false
`--trace-turbo-inlining`	trace TurboFan inlining	bool	false
`--inline-accessors`	inline JavaScript accessors	bool	true
`--inline-into-try`	inline into try blocks	bool	true
`--turbo-inline-array-builtins`	inline array builtins in TurboFan code	bool	true
`--use-osr`	use on-stack replacement	bool	true
`--trace-osr`	trace on-stack replacement	bool	false
`--analyze-environment-liveness`	analyze liveness of environment slots and zap dead values	bool	true
`--trace-environment-liveness`	trace liveness of local variable slots	bool	false
`--turbo-load-elimination`	enable load elimination in TurboFan	bool	true
`--trace-turbo-load-elimination`	trace TurboFan load elimination	bool	false
`--turbo-profiling`	enable profiling in TurboFan	bool	false
`--turbo-verify-allocation`	verify register allocation in TurboFan	bool	false
`--turbo-move-optimization`	optimize gap moves in TurboFan	bool	true
`--turbo-jt`	enable jump threading in TurboFan	bool	true
`--turbo-loop-peeling`	Turbofan loop peeling	bool	true
`--turbo-loop-variable`	Turbofan loop variable optimization	bool	true
`--turbo-cf-optimization`	optimize control flow in TurboFan	bool	true
`--turbo-escape`	enable escape analysis	bool	true
`--turbo-allocation-folding`	Turbofan allocation folding	bool	true
`--turbo-instruction-scheduling`	enable instruction scheduling in TurboFan	bool	false
`--turbo-stress-instruction-scheduling`	randomly schedule instructions to stress dependency tracking	bool	false
`--turbo-store-elimination`	enable store-store elimination in TurboFan	bool	true
`--trace-store-elimination`	trace store elimination	bool	false
`--turbo-rewrite-far-jumps`	rewrite far to near jumps	ia32,x64	bool
`--experimental-inline-promise-constructor`	inline the Promise constructor in TurboFan	bool	true
`--untrusted-code-mitigations`	Enable mitigations for executing untrusted code	bool	false
`--branch-load-poisoning`	Mask loads with branch conditions.	bool	false
`--minimal`	simplifies execution model to make porting easier	e.g. always use Ignition, never optimize	bool
`--expose-wasm`	expose wasm interface to JavaScript	bool	true
`--assume-asmjs-origin`	force wasm decoder to assume input is internal asm-wasm format	bool	false
`--wasm-disable-structured-cloning`	disable wasm structured cloning	bool	false
`--wasm-num-compilation-tasks`	number of parallel compilation tasks for wasm	int	10
`--wasm-write-protect-code-memory`	write protect code memory on the wasm native heap	bool	false
`--wasm-trace-serialization`	trace serialization/deserialization	bool	false
`--wasm-async-compilation`	enable actual asynchronous compilation for WebAssembly.compile	bool	true
`--wasm-test-streaming`	use streaming compilation instead of async compilation for tests	bool	false
`--wasm-max-mem-pages`	maximum number of 64KiB memory pages of a wasm instance	uint	32767
`--wasm-max-table-size`	maximum table size of a wasm instance	uint	10000000
`--wasm-tier-up`	enable wasm baseline compilation and tier up to the optimizing compiler	bool	true
`--trace-wasm-ast-start`	start function for wasm AST trace	inclusive	int
`--trace-wasm-ast-end`	end function for wasm AST trace	exclusive	int
`--liftoff`	enable Liftoff, the baseline compiler for WebAssembly	bool	true
`--wasm-trace-memory`	print all memory updates performed in wasm code	bool	false
`--wasm-tier-mask-for-testing`	bitmask of functions to compile with TurboFan instead of Liftoff	int	0
`--validate-asm`	validate asm.js modules before compiling	bool	true
`--suppress-asm-messages`	don’t emit asm.js related messages	for golden file testing	bool
`--trace-asm-time`	log asm.js timing info to the console	bool	false
`--trace-asm-scanner`	log tokens encountered by asm.js scanner	bool	false
`--trace-asm-parser`	verbose logging of asm.js parse failures	bool	false
`--stress-validate-asm`	try to validate everything as asm.js	bool	false
`--dump-wasm-module-path`	directory to dump wasm modules to	string	nullptr
`--experimental-wasm-mv`	enable prototype multi-value support for wasm	bool	false
`--experimental-wasm-eh`	enable prototype exception handling opcodes for wasm	bool	false
`--experimental-wasm-se`	enable prototype sign extension opcodes for wasm	bool	true
`--experimental-wasm-sat-f2i-conversions`	enable prototype saturating float conversion opcodes for wasm	bool	false
`--experimental-wasm-threads`	enable prototype thread opcodes for wasm	bool	false
`--experimental-wasm-simd`	enable prototype SIMD opcodes for wasm	bool	false
`--experimental-wasm-anyref`	enable prototype anyref opcodes for wasm	bool	false
`--experimental-wasm-mut-global`	enable prototype import/export mutable global support for wasm	bool	true
`--wasm-opt`	enable wasm optimization	bool	false
`--wasm-no-bounds-checks`	disable bounds checks	performance testing only	bool
`--wasm-no-stack-checks`	disable stack checks	performance testing only	bool
`--wasm-shared-engine`	shares one wasm engine between all isolates within a process	bool	true
`--wasm-shared-code`	shares code underlying a wasm module when it is transferred	bool	true
`--wasm-trap-handler`	use signal handlers to catch out of bounds memory access in wasm	currently Linux x86_64 only	bool
`--wasm-trap-handler-fallback`	Use bounds checks if guarded memory is not available	bool	false
`--wasm-fuzzer-gen-test`	Generate a test case when running a wasm fuzzer	bool	false
`--print-wasm-code`	Print WebAssembly code	bool	false
`--wasm-interpret-all`	Execute all wasm code in the wasm interpreter	bool	false
`--asm-wasm-lazy-compilation`	enable lazy compilation for asm-wasm modules	bool	true
`--wasm-lazy-compilation`	enable lazy compilation for all wasm modules	bool	false
`--frame-count`	number of stack frames inspected by the profiler	int	1
`--type-info-threshold`	percentage of ICs that must have type info to allow optimization	int	25
`--stress-sampling-allocation-profiler`	Enables sampling allocation profiler with X as a sample interval	int	0
`--min-semi-space-size`	min size of a semi-space	in MBytes), the new space consists of two semi-spaces	size_t
`--max-semi-space-size`	max size of a semi-space	in MBytes), the new space consists of two semi-spaces	size_t
`--semi-space-growth-factor`	factor by which to grow the new space	int	2
`--experimental-new-space-growth-heuristic`	Grow the new space based on the percentage of survivors instead of their absolute value.	bool	false
`--max-old-space-size`	max size of the old space	in Mbytes	size_t
`--initial-old-space-size`	initial old space size	in Mbytes	size_t
`--gc-global`	always perform global GCs	bool	false
`--random-gc-interval`	Collect garbage after random(0, X allocations. It overrides gc_interval.	int	0
`--gc-interval`	garbage collect after allocations	int	-1
`--retain-maps-for-n-gc`	keeps maps alive for old space garbage collections	int	2
`--trace-gc`	print one trace line following each garbage collection	bool	false
`--trace-gc-nvp`	print one detailed trace line in name=value format after each garbage collection	bool	false
`--trace-gc-ignore-scavenger`	do not print trace line after scavenger collection	bool	false
`--trace-idle-notification`	print one trace line following each idle notification	bool	false
`--trace-idle-notification-verbose`	prints the heap state used by the idle notification	bool	false
`--trace-gc-verbose`	print more details following each garbage collection	bool	false
`--trace-allocation-stack-interval`	print stack trace after free-list allocations	int	-1
`--trace-duplicate-threshold-kb`	print duplicate objects in the heap if their size is more than given threshold	int	0
`--trace-fragmentation`	report fragmentation for old space	bool	false
`--trace-fragmentation-verbose`	report fragmentation for old space	detailed	bool
`--trace-evacuation`	report evacuation statistics	bool	false
`--trace-mutator-utilization`	print mutator utilization, allocation speed, gc speed	bool	false
`--incremental-marking`	use incremental marking	bool	true
`--incremental-marking-wrappers`	use incremental marking for marking wrappers	bool	true
`--trace-unmapper`	Trace the unmapping	bool	false
`--parallel-scavenge`	parallel scavenge	bool	true
`--trace-parallel-scavenge`	trace parallel scavenge	bool	false
`--write-protect-code-memory`	write protect code memory	bool	true
`--concurrent-marking`	use concurrent marking	bool	true
`--parallel-marking`	use parallel marking in atomic pause	bool	true
`--ephemeron-fixpoint-iterations`	number of fixpoint iterations it takes to switch to linear ephemeron algorithm	int	10
`--trace-concurrent-marking`	trace concurrent marking	bool	false
`--black-allocation`	use black allocation	bool	true
`--concurrent-store-buffer`	use concurrent store buffer processing	bool	true
`--concurrent-sweeping`	use concurrent sweeping	bool	true
`--parallel-compaction`	use parallel compaction	bool	true
`--parallel-pointer-update`	use parallel pointer update during compaction	bool	true
`--detect-ineffective-gcs-near-heap-limit`	trigger out-of-memory failure to avoid GC storm near heap limit	bool	true
`--trace-incremental-marking`	trace progress of the incremental marking	bool	false
`--trace-stress-marking`	trace stress marking progress	bool	false
`--trace-stress-scavenge`	trace stress scavenge progress	bool	false
`--track-gc-object-stats`	track object counts and memory usage	bool	false
`--trace-gc-object-stats`	trace object counts and memory usage	bool	false
`--trace-zone-stats`	trace zone memory usage	bool	false
`--track-retaining-path`	enable support for tracking retaining path	bool	false
`--concurrent-array-buffer-freeing`	free array buffer allocations on a background thread	bool	true
`--gc-stats`	Used by tracing internally to enable gc statistics	int	0
`--track-detached-contexts`	track native contexts that are expected to be garbage collected	bool	true
`--trace-detached-contexts`	trace native contexts that are expected to be garbage collected	bool	false
`--move-object-start`	enable moving of object starts	bool	true
`--memory-reducer`	use memory reducer	bool	true
`--heap-growing-percent`	specifies heap growing factor as	1 + heap_growing_percent/100	int
`--v8-os-page-size`	override OS page size	in KBytes	int
`--always-compact`	Perform compaction on every full GC	bool	false
`--never-compact`	Never perform compaction on full GC - testing only	bool	false
`--compact-code-space`	Compact code space on full collections	bool	true
`--use-marking-progress-bar`	Use a progress bar to scan large objects in increments when incremental marking is active.	bool	true
`--force-marking-deque-overflows`	force overflows of marking deque by reducing it’s size to 64 words	bool	false
`--stress-compaction`	stress the GC compactor to flush out bugs	implies —force_marking_deque_overflows	bool
`--stress-compaction-random`	Stress GC compaction by selecting random percent of pages as evacuation candidates. It overrides stress_compaction.	bool	false
`--stress-incremental-marking`	force incremental marking for small heaps and run it more often	bool	false
`--fuzzer-gc-analysis`	prints number of allocations and enables analysis mode for gc fuzz testing, e.g. —stress-marking, —stress-scavenge	bool	false
`--stress-marking`	force marking at random points between 0 and X	inclusive percent of the regular marking start limit	int
`--stress-scavenge`	force scavenge at random points between 0 and X	inclusive percent of the new space capacity	int
`--disable-abortjs`	disables AbortJS runtime function	bool	false
`--manual-evacuation-candidates-selection`	Test mode only flag. It allows an unit test to select evacuation candidates pages	requires —stress_compaction).	bool
`--fast-promotion-new-space`	fast promote new space on high survival rates	bool	false
`--clear-free-memory`	initialize free memory with 0	bool	false
`--young-generation-large-objects`	allocates large objects by default in the young generation large object space	bool	false
`--debug-code`	generate extra code	assertions for debugging	bool
`--code-comments`	emit comments in code disassembly; for more readable source positions you should add —no-concurrent_recompilation	bool	false
`--enable-sse3`	enable use of SSE3 instructions if available	bool	true
`--enable-ssse3`	enable use of SSSE3 instructions if available	bool	true
`--enable-sse4-1`	enable use of SSE4.1 instructions if available	bool	true
`--enable-sahf`	enable use of SAHF instruction if available	X64 only	bool
`--enable-avx`	enable use of AVX instructions if available	bool	true
`--enable-fma3`	enable use of FMA3 instructions if available	bool	true
`--enable-bmi1`	enable use of BMI1 instructions if available	bool	true
`--enable-bmi2`	enable use of BMI2 instructions if available	bool	true
`--enable-lzcnt`	enable use of LZCNT instruction if available	bool	true
`--enable-popcnt`	enable use of POPCNT instruction if available	bool	true
`--arm-arch`	generate instructions for the selected ARM architecture if available: armv6, armv7, armv7+sudiv or armv8	string	armv8
`--force-long-branches`	force all emitted branches to be in long mode	MIPS/PPC only	bool
`--mcpu`	enable optimization for specific cpu	string	auto
`--partial-constant-pool`	enable use of partial constant pools	X64 only	bool
`--enable-armv7`	deprecated	use —arm_arch instead	maybe_bool
`--enable-vfp3`	deprecated	use —arm_arch instead	maybe_bool
`--enable-32dregs`	deprecated	use —arm_arch instead	maybe_bool
`--enable-neon`	deprecated	use —arm_arch instead	maybe_bool
`--enable-sudiv`	deprecated	use —arm_arch instead	maybe_bool
`--enable-armv8`	deprecated	use —arm_arch instead	maybe_bool
`--enable-regexp-unaligned-accesses`	enable unaligned accesses for the regexp engine	bool	true
`--script-streaming`	enable parsing on background	bool	true
`--disable-old-api-accessors`	Disable old-style API accessors whose setters trigger through the prototype chain	bool	false
`--expose-natives-as`	expose natives in global object	string	nullptr
`--expose-free-buffer`	expose freeBuffer extension	bool	false
`--expose-gc`	expose gc extension	bool	false
`--expose-gc-as`	expose gc extension under the specified name	string	nullptr
`--expose-externalize-string`	expose externalize string extension	bool	false
`--expose-trigger-failure`	expose trigger-failure extension	bool	false
`--stack-trace-limit`	number of stack frames to capture	int	10
`--builtins-in-stack-traces`	show built-in functions in stack traces	bool	false
`--enable-experimental-builtins`	enable new csa-based experimental builtins	bool	false
`--disallow-code-generation-from-strings`	disallow eval and friends	bool	false
`--expose-async-hooks`	expose async_hooks object	bool	false
`--allow-unsafe-function-constructor`	allow invoking the function constructor without security checks	bool	false
`--force-slow-path`	always take the slow path for builtins	bool	false
`--inline-new`	use fast inline allocation	bool	true
`--trace`	trace function calls	bool	false
`--lazy`	use lazy compilation	bool	true
`--trace-opt`	trace lazy optimization	bool	false
`--trace-opt-verbose`	extra verbose compilation tracing	bool	false
`--trace-opt-stats`	trace lazy optimization statistics	bool	false
`--trace-deopt`	trace optimize function deoptimization	bool	false
`--trace-file-names`	include file names in trace-opt/trace-deopt output	bool	false
`--trace-interrupts`	trace interrupts when they are handled	bool	false
`--opt`	use adaptive optimizations	bool	true
`--always-opt`	always try to optimize functions	bool	false
`--always-osr`	always try to OSR functions	bool	false
`--prepare-always-opt`	prepare for turning on always opt	bool	false
`--trace-serializer`	print code serializer trace	bool	false
`--compilation-cache`	enable compilation cache	bool	true
`--cache-prototype-transitions`	cache prototype transitions	bool	true
`--compiler-dispatcher`	enable compiler dispatcher	bool	false
`--trace-compiler-dispatcher`	trace compiler dispatcher activity	bool	false
`--trace-compiler-dispatcher-jobs`	trace progress of individual jobs managed by the compiler dispatcher	bool	false
`--cpu-profiler-sampling-interval`	CPU profiler sampling interval in microseconds	int	1000
`--trace-js-array-abuse`	trace out-of-bounds accesses to JS arrays	bool	false
`--trace-external-array-abuse`	trace out-of-bounds-accesses to external arrays	bool	false
`--trace-array-abuse`	trace out-of-bounds accesses to all arrays	bool	false
`--trace-side-effect-free-debug-evaluate`	print debug messages for side-effect-free debug-evaluate for testing	bool	false
`--hard-abort`	abort by crashing	bool	true
`--expose-inspector-scripts`	expose injected-script-source.js for debugging	bool	false
`--stack-size`	default size of stack region v8 is allowed to use	in kBytes	int
`--max-stack-trace-source-length`	maximum length of function source code printed in a stack trace.	int	300
`--clear-exceptions-on-js-entry`	clear pending exceptions when entering JavaScript	bool	false
`--histogram-interval`	time interval in ms for aggregating memory histograms	int	600000
`--heap-profiler-trace-objects`	Dump heap object allocations/movements/size_updates	bool	false
`--heap-profiler-use-embedder-graph`	Use the new EmbedderGraph API to get embedder nodes	bool	true
`--heap-snapshot-string-limit`	truncate strings to this length in the heap snapshot	int	1024
`--sampling-heap-profiler-suppress-randomness`	Use constant sample intervals to eliminate test flakiness	bool	false
`--use-idle-notification`	Use idle notification to reduce memory footprint.	bool	true
`--use-ic`	use inline caching	bool	true
`--trace-ic`	trace inline cache state transitions for tools/ic-processor	bool	false
`--ic-stats`	inline cache state transitions statistics	int	0
`--native-code-counters`	generate extra code for manipulating stats counters	bool	false
`--thin-strings`	Enable ThinString support	bool	true
`--trace-prototype-users`	Trace updates to prototype user tracking	bool	false
`--use-verbose-printer`	allows verbose printing	bool	true
`--trace-for-in-enumerate`	Trace for-in enumerate slow-paths	bool	false
`--trace-maps`	trace map creation	bool	false
`--trace-maps-details`	also log map details	bool	true
`--allow-natives-syntax`	allow natives syntax	bool	false
`--lazy-inner-functions`	enable lazy parsing inner functions	bool	true
`--aggressive-lazy-inner-functions`	even lazier inner function parsing	bool	true
`--preparser-scope-analysis`	perform scope analysis for preparsed inner functions	bool	true
`--trace-sim`	Trace simulator execution	bool	false
`--debug-sim`	Enable debugging the simulator	bool	false
`--check-icache`	Check icache flushes in ARM and MIPS simulator	bool	false
`--stop-sim-at`	Simulator stop after x number of instructions	int	0
`--sim-stack-alignment`	Stack alingment in bytes in simulator	4 or 8, 8 is default	int
`--sim-stack-size`	Stack size of the ARM64, MIPS64 and PPC64 simulator in kBytes	default is 2 MB	int
`--log-colour`	When logging, try to use coloured output.	bool	true
`--ignore-asm-unimplemented-break`	Don’t break for ASM_UNIMPLEMENTED_BREAK macros.	bool	false
`--trace-sim-messages`	Trace simulator debug messages. Implied by —trace-sim.	bool	false
`--stack-trace-on-illegal`	print stack trace when an illegal exception is thrown	bool	false
`--abort-on-uncaught-exception`	abort program	dump core when an uncaught exception is thrown	bool
`--abort-on-stack-or-string-length-overflow`	Abort program when the stack overflows or a string exceeds maximum length	as opposed to throwing RangeError). This is useful for fu`zzing where the spec behaviour would introduce nondeterminism.`	bool
`--randomize-hashes`	randomize hashes to avoid predictable hash collisions	with snapshots this option cannot override the baked-in seed	bool
`--rehash-snapshot`	rehash strings from the snapshot to override the baked-in seed	bool	true
`--hash-seed`	Fixed seed to use to hash property keys	0 means random)(with snapshots this option cannot override the baked-in seed	uint64
`--random-seed`	Default seed for initializing random generator	0, the default, means to use system random).	int
`--fuzzer-random-seed`	Default seed for initializing fuzzer random generator	0, the default, means to use v8’s random number generator seed).	int
`--trace-rail`	trace RAIL mode	bool	false
`--print-all-exceptions`	print exception object and stack trace on each thrown exception	bool	false
`--runtime-call-stats`	report runtime call counts and times	bool	false
`--runtime-stats`	internal usage only for controlling runtime statistics	int	0
`--print-embedded-builtin-candidates`	Prints builtins that are not yet embedded but could be.	bool	false
`--lazy-deserialization`	Deserialize code lazily from the snapshot.	bool	true
`--lazy-handler-deserialization`	Deserialize bytecode handlers lazily from the snapshot.	bool	true
`--trace-lazy-deserialization`	Trace lazy deserialization.	bool	false
`--profile-deserialization`	Print the time it takes to deserialize the snapshot.	bool	false
`--serialization-statistics`	Collect statistics on serialized objects.	bool	false
`--serialization-chunk-size`	Custom size for serialization chunks	uint	4096
`--regexp-optimization`	generate optimized regexp code	bool	true
`--regexp-mode-modifiers`	enable inline flags in regexp.	bool	false
`--testing-bool-flag`	testing_bool_flag	bool	true
`--testing-maybe-bool-flag`	testing_maybe_bool_flag	maybe_bool	unset
`--testing-int-flag`	testing_int_flag	int	13
`--testing-float-flag`	float-flag	float	2.5
`--testing-string-flag`	string-flag	string	Hello, world!
`--testing-prng-seed`	Seed used for threading test randomness	int	42
`--embedded-src`	Path for the generated embedded data file.	mksnapshot only	string
`--embedded-variant`	Label to disambiguate symbols in embedded data file.	mksnapshot only	string
`--startup-src`	Write V8 startup as C++ src.	mksnapshot only	string
`--startup-blob`	Write V8 startup blob file.	mksnapshot only	string
`--help`	Print usage message, including flags, on console	bool	true
`--dump-counters`	Dump counters on exit	bool	false
`--dump-counters-nvp`	Dump counters as name-value pairs on exit	bool	false
`--use-external-strings`	Use external strings for source code	bool	false
`--map-counters`	Map counters to a file	string
`--js-arguments`	Pass all remaining arguments to the script. Alias for ”—“.	arguments
`--mock-arraybuffer-allocator`	Use a mock ArrayBuffer allocator for testing.	bool	false
`--log`	Minimal logging	no API, code, GC, suspect, or handles samples).	bool
`--log-all`	Log all events to the log file.	bool	false
`--log-api`	Log API events to the log file.	bool	false
`--log-code`	Log code events to the log file without profiling.	bool	false
`--log-handles`	Log global handle events.	bool	false
`--log-suspect`	Log suspect operations.	bool	false
`--log-source-code`	Log source code.	bool	false
`--log-function-events`	Log function events	parse, compile, execute separately.	bool
`--prof`	Log statistical profiling information	implies —log-code).	bool
`--detailed-line-info`	Always generate detailed line information for CPU profiling.	bool	false
`--prof-sampling-interval`	Interval for —prof samples	in microseconds).	int
`--prof-cpp`	Like —prof, but ignore generated code.	bool	false
`--prof-browser-mode`	Used with —prof, turns on browser-compatible mode for profiling.	bool	true
`--logfile`	Specify the name of the log file.	string	v8.log
`--logfile-per-isolate`	Separate log files for each isolate.	bool	true
`--ll-prof`	Enable low-level linux profiler.	bool	false
`--interpreted-frames-native-stack`	Show interpreted frames on the native stack	useful for external profilers).	bool
`--perf-basic-prof`	Enable perf linux profiler	basic support).	bool
`--perf-basic-prof-only-functions`	Only report function code ranges to perf	i.e. no stubs).	bool
`--perf-prof`	Enable perf linux profiler	experimental annotate support).	bool
`--perf-prof-unwinding-info`	Enable unwinding info for perf linux profiler	experimental).	bool
`--gc-fake-mmap`	Specify the name of the file for fake gc mmap used in ll_prof	string	/tmp/v8_gc
`--log-internal-timer-events`	Time internal events.	bool	false
`--log-timer-events`	Time events including external callbacks.	bool	false
`--log-instruction-stats`	Log AArch64 instruction statistics.	bool	false
`--log-instruction-file`	AArch64 instruction statistics log file.	string	arm64_inst.csv
`--log-instruction-period`	AArch64 instruction statistics logging period.	int	4194304
`--redirect-code-traces`	output deopt information and disassembly into file code--.asm	bool	false
`--redirect-code-traces-to`	output deopt information and disassembly into the given file	string	nullptr
`--print-opt-source`	print source code of optimized and inlined functions	bool	false
`--trace-elements-transitions`	trace elements transitions	bool	false
`--trace-creation-allocation-sites`	trace the creation of allocation sites	bool	false
`--print-code-stubs`	print code stubs	bool	false
`--test-secondary-stub-cache`	test secondary stub cache by disabling the primary one	bool	false
`--test-primary-stub-cache`	test primary stub cache by disabling the secondary one	bool	false
`--test-small-max-function-context-stub-size`	enable testing the function context size overflow path by making the maximum size smaller	bool	false
`--print-code`	print generated code	bool	false
`--print-opt-code`	print optimized code	bool	false
`--print-opt-code-filter`	filter for printing optimized code	string	*
`--print-code-verbose`	print more information for code	bool	false
`--print-builtin-code`	print generated code for builtins	bool	false
`--print-builtin-code-filter`	filter for printing builtin code	string	*
`--print-builtin-size`	print code size for builtins	bool	false
`--sodium`	print generated code output suitable for use with the Sodium code viewer	bool	false
`--print-all-code`	enable all flags related to printing code	bool	false
`--predictable`	enable predictable mode	bool	false
`--single-threaded`	disable the use of background tasks	bool	false
`--single-threaded-gc`	disable the use of background gc tasks	bool	false

Written on Feb 15, 2019

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