React 18.2.0 (latest) - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 109910 bytes (107.3k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 10737 bytes (10.5k, 10%).

After GZIP compression these minified files vary in size:

gzip -6 (default)	4275 bytes (4.2k)	local copy
gzip -9	4275 bytes (4.2k)	local copy
Boot	4269 bytes (4.2k)	CDN
cdnjs	4269 bytes (4.2k)	CDN
libdeflate -12	4190 bytes (4.1k)	local copy
7zip -mx=9 -tgzip	4189 bytes (4.1k)	local copy
pigz -11 -n	4189 bytes (4.1k)	local copy
zultra	4189 bytes (4.1k)	local copy
kzip -s0 -rn -b0	4187 bytes (4.1k)	local copy
Zopfli	4180 bytes (4.1k)	local copy
Zopfli (defluff)	4179 bytes (4.1k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/react/react-18.2.0.min.js (or via HTTPS)

You will automatically get the smallest React 18.2.0 file, ETag caching is available and
if your browser doesn't support GZIP decompression then the uncompressed version will be sent.

Currently best Zopfli settings

Save 89 bytes by using my React 18.2.0 Zopfli version instead of the best available CDN (2.13% smaller than cdnjs, 4180 vs. 4269 bytes):

Download

You can use my super-compressed files for whatever purpose you like as long as you respect the library's original license agreement.
There are no restrictions from my side - but please avoid hot-linking if you run a high-traffic website.

These command-line settings yielded the best compression ratio so far (Linux version of zopfli-krzymod):
zopfli --i100000 --mb8 --mls4096 --bsr6 --lazy --ohh

(found July 4, 2022)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	4096	--mls4096
block splitting recursion	6	--bsr6
lazy matching in LZ77	yes	--lazy
optimized Huffman headers	yes	--ohh
initial random W for iterations	1	--rw1
initial random Z for iterations	2	--rz2

Even Smaller Files Thanks To Defluff

Zopfli's output can be further optimized by the defluff tool.
In this particular case, defluff saves 1 more byte (4179 bytes).

Download

Verify file integrity

After decompression, my uncompressed files are identical to the original ones:

MD5:
curl --silent --compressed https://fb.me/react-18.2.0.min.js --location | md5sum
d86dcdbfed4c273c4742744941259902 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-18.2.0.min.zopfli.js.gz | md5sum
d86dcdbfed4c273c4742744941259902 -

SHA1:
curl --silent --compressed https://fb.me/react-18.2.0.min.js --location | sha1sum
98089a33d0cf2fa4b3e1ba9b7eeb9b8ba0ac82a7 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-18.2.0.min.zopfli.js.gz | sha1sum
98089a33d0cf2fa4b3e1ba9b7eeb9b8ba0ac82a7 -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	4269 bytes	d86dcdbfed4c273c4742744941259902	June 15, 2022 @ 05:20
cdnjs	4269 bytes	d86dcdbfed4c273c4742744941259902	June 14, 2022 @ 22:06

Note: only the MD5 hashes are shown to keep things simple.

Other Versions

Available React versions at minime.stephan-brumme.com:

18.2.0,
18.1.0, 18.0.0,
17.0.2, 17.0.1, 17.0.0,
16.14.0,
16.13.1, 16.13.0,
16.12.0,
16.11.0,
16.10.2, 16.10.1, 16.10.0,
16.9.0,
16.8.6, 16.8.5, 16.8.4, 16.8.3, 16.8.2, 16.8.1, 16.8.0,
16.7.0,
16.6.3, 16.6.1, 16.6.0,
16.5.2, 16.5.1, 16.5.0,
16.4.2, 16.4.1, 16.4.0,
16.3.2, 16.3.1, 16.3.0,
16.2.0,
16.1.1, 16.1.0, 16.0.0,
15.6.2, 15.6.1, 15.6.0,
15.5.2, 15.5.1, 15.5.0,
15.4.2, 15.4.1, 15.4.0,
15.3.2, 15.3.1, 15.3.0,
15.2.1, 15.2.0,
15.1.0,
15.0.2, 15.0.1, 15.0.0,
0.14.8, 0.14.7, 0.14.6, 0.14.5, 0.14.4, 0.14.3, 0.14.2, 0.14.1, 0.14.0,
0.13.3, 0.13.2, 0.13.1, 0.13.0,
0.12.2, 0.12.1, 0.12.0,
0.11.2, 0.11.1, 0.11.0,
0.10.0

The project site contains an overview how well these versions were compressed.
Other interesting projects are AngularJS, BackboneJS, Bootstrap, D3, Dojo, Ember, jQuery, Knockout, lodash, Socket.IO, ThreeJS, UnderscoreJS and Vue.

Changelog

Best Zopfli parameters so far:

Size	Improvement	Parameters	Found
4180 bytes	-1 byte	zopfli --i100000 --mls4096 --bsr6 --lazy --ohh	July 4, 2022 @ 12:02
4181 bytes	-1 byte	zopfli --i10000 --mls4096 --bsr6 --lazy --ohh	June 30, 2022 @ 12:27
4182 bytes	-1 byte	zopfli --i10000 --mls4096 --bsr8 --lazy --ohh	June 30, 2022 @ 12:15
4183 bytes	-2 bytes	zopfli --i1000 --mls4096 --bsr16 --lazy --ohh	June 30, 2022 @ 11:57
4185 bytes	–	zopfli --i100 --mls4096 --bsr11 --lazy --ohh	June 30, 2022 @ 11:18

If there are multiple parameter sets yielding the same compressed size, only the first one found is shown.

Most recent activity on July 4, 2022 @ 15:58.

Heatmaps

This Zopfli heatmap visualizes how compression changes when modifying the --bsr and --mls parameter.
Cell's contents is the best filesize achieved (in bytes, hover with mouse over cells to see number of iterations).

Good parameters are green, bad are red. The best and worst are bold as well.
The brightness of the blue background color indicates how many iterations were processed:
10,000, 100,000 or 1,000,000.

bsr \ mls	2	4	8	16	32	64	128	256	512	1024	2048	4096	8192	16384	32768
bsr \ mls	2	4	8	16	32	64	128	256	512	1024	2048	4096	8192	16384	32768
2	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4187	4187	4188	4188
4	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4181	4186	4186
6	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4180	4185	4185	4185
7	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4185	4183	4183
8	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4180	4187	4187	4187
9	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4185	4185	4185
10	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4184	4185	4185
11	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4187	4187	4187
12	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4185	4185	4185	4185
13	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4185	4185	4185	4185
14	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4186	4185	4185
15	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4185	4183	4185	4185
16	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4185	4185	4185
17	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4185	4185	4185
18	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4185	4185	4185
19	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4183	4185	4185
20	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4185	4185	4185
21	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4185	4187	4187
22	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4183	4183	4185	4185
23	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4187	4187	4187
25	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4180	4185	4184	4184
30	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4185	4185	4185
40	4187	4187	4187	4187	4187	4187	4187	4187	4187	4187	4188	4181	4185	4185	4185

Due to the Monte Carlo design of my search algorithm, not all parameters have reached the same number of iterations yet:

Iterations	Min. Bytes	Reduction	Coverage
100	4185 bytes	–	100%
1,000	4183 bytes	-2 bytes	100%
10,000	4181 bytes	-2 bytes	100%
100,000	4180 bytes	-1 byte	3.48%
1,000,000	4180 bytes	–	0.87%
10,000,000	–	–	–

KZIP has far less options available for tuning/optimization. I only played around with the number of blocks (parameter -n):

Blocks	Min. Bytes	Compared To Best Zopfli	Compared To Best KZIP
(any)	4187 bytes	+7 bytes (+0.17%)	–
1	4187 bytes	+7 bytes (+0.17%)	–
2	4220 bytes	+40 bytes (+0.96%)	+33 bytes
3	4234 bytes	+54 bytes (+1.29%)	+47 bytes
4	4259 bytes	+79 bytes (+1.89%)	+72 bytes
5	4294 bytes	+114 bytes (+2.73%)	+107 bytes
6	4320 bytes	+140 bytes (+3.35%)	+133 bytes
7	4352 bytes	+172 bytes (+4.11%)	+165 bytes
8	4385 bytes	+205 bytes (+4.90%)	+198 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
However, support for Brotli is constantly growing - but your browser doesn't support it.

Algorithm	Program	Parameters	Size	Compared To Best Zopfli
Brotli (Wikipedia)	brotli	brotli -q 11	3747 bytes	-433 bytes (-10.36%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	3867 bytes	-313 bytes (-7.49%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	4187 bytes	+7 bytes (+0.17%)
Zstandard (Wikipedia)	zstd	zstd -19	4189 bytes	+9 bytes (+0.22%)
LZMA2 (Wikipedia)	xz	xz -9	4240 bytes	+60 bytes (+1.44%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	4309 bytes	+129 bytes (+3.09%)
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	4644 bytes	+464 bytes (+11.10%)

Detailled Analysis

I wrote a DEFLATE decoder in Javascript. Click the button below to start a client-side analysis of the smallest gzipped files (may take a second):

Load and Parse Data

Notes: pigz is a fast open source multi-threaded implementation of gzip written by one of the original authors of gzip.
However, when using compression level 11, pigz actually switches to the slower Zopfli algorithm and isn't multi-threaded anymore.
KrzyMOD's extensions to Zopfli offer the highest level of configuration and is therefore used for my brute-force search.
Ken Silverman wrote the closed-source KZIP compression program and Jonathon Fowler ported it to Linux.
Defluff was created by Joachim Henke; DeflOpt is a tool by Ben Jos Walbeehm.

website made by Stephan Brumme in 2015 and still improving in 2024.
all timestamps are displayed in central european time. see my changelog.
no flash, not even images or external css files - and everything squeezed into a single html file.
which was handsomely compressed before releasing it into the wild internet - obviously.

please visit my homepage and my blog, too.
email: minime (at) stephan-brumme.com

All trademarks are property of their respective owners. You know, the boring legal stuff.