I've ported a bunch of hash functons to JS. These are all highly optimized for speed, and make use of ES6 features like Math.imul and default parameters. Sadly, only algorithms made for 32-bit architectures get good performance in JS. Emulating 64-bit math can decrease performance by 80-90%.

Also see: CRC functions

32-bit

Algorithm	Hash size	Speed	Notes
CRC-32	32-bit	147/575	For speed reference (it's pretty slow)
FNV	32-bit	3041/2649	variants: FNV-0, FNV-1, FNV-1a, FNV-1a_BM
MurmurHash1	32-bit	3296/2822	Original version. Super fast.
MurmurHash2	32-bit	3027/2518	aka MurmurHash2_x86_32
MurmurHash2A	32-bit	3053/2484	Fixes a flaw in MurmurHash2. Uses Merkle–Damgård construction.
MurmurHash3	32-bit	3090/2515	aka MurmurHash3_x86_32
xxHash	32-bit	2968/2492	not as fast as you'd think, but still good
SuperFastHash	32-bit	-/-	Higher collision rates in some cases: 90 of 131072 (vs. Murmur3=0, Lookup2=2, Lookup3=3, xxHash=4)
Marvin32	32-bit	-/-	Obscure function, but seems decent. Almost as fast as MurmurHash3.
CityHash32	32-bit	-/-	The only 32-bit variant in Google's City/Farm families. Not recommended, it's just a slower Murmur3 clone.
FunnyHash32	32-bit	-/-	Yet another 32-bit hash.

64-bit or higher

Algorithm	Hash size	Speed	Notes
Lookup2_x86	32-bit	2412/1985	(Obsolete) 32-bit. 64/96-bit is possible but with worse statistics.
Lookup3_x86	32/64-bit	2553/1038	32 or 64-bit. 96 is possible but with weaker statistics.
MurmurHash2_x86_64	64-bit	2759/2406	Slightly modified to avoid a flaw in the original, see comments.
MurmurHash3_x86_128	128-bit	2498/2162	Modified version. Contains a possible flaw, see comments.
MurmurHash2_160	160-bit	1968/1590	Unofficial mod that outputs five 32-bit hash states.
HalfSipHash	32/64-bit	-/-	32-bit version of SipHash. Can output a 64-bit hash. Kind of slow.

Performance notes

Legend (for Speed): 256 / 31488 (InputLength)

These numbers don't really mean much, just a quick comparison. They're all pretty fast. My fastest table CRC-32 is still ~75% slower than MurmurHash2_160, which is the slowest in the table above.

• MurmurHash3_x86_128 seems really fast considering it outputs 4 hashes, possibly one of the best choices for >32-bit.
• MurmurHash1 is fastest 32-bit hash in JS. MurmurHash3 and xxHash are also very good for high quality hash.
• If xxHash can be modified to properly mix v0-v4, this might be an efficient hash >32-bit.
• lookup2 produces 3 hahses, but its quality is only ensured for one of them.
• lookup3 is faster for 256, but is REALLY SLOW for 31488 (investigate). Unlike lookup2, its quality is ensured for 64-bit.
• I cannot recommend MurmurHash2_x86_64 because of its flaw, and my modification that attempts to fix it needs to be benchmarked.
• MurmurHash2_160 is only one more 32-bit hash larger than MurmurHash3_x86_128 but is quite slower. And cannot downscale without possibly hurting quality.
• CybBeta2 is my custom 64-bit hash. Decent speed, but not much faster than MurmurHash2_x86_64 and has untested hash quality.
• CybBeta0 is my custom 32-bit hash. Only slightly faster than MurmurHash1 and has untested hash quality.

Emulated 64-bit hash functions

I will put ports of 64-bit arithmetic hash functions here, but expect them to be extremely slow. If WebAssembly becomes viable that can be useful for 64-bit hash functions. BigInt does not currently seem to be a performant option.

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Misc benchmarks

• https://jsbench.me/fyjfja4xih/1 - MurmurHash3 benchmarks
• https://jsbench.me/2hjfj9oscd/1 - xxHash benchmarks
• https://jsbench.me/isjfj2rpkx/1 - comparison of available implementations
• https://jsbench.me/tgjfegz4er/1 - the guds
• https://jsbench.me/zrjfehfwgu/1 - the not-so-guds