React 16.3.0 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 56156 bytes (54.8k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 6867 bytes (6.7k, 12%).

After GZIP compression these minified files vary in size:

Boot	3138 bytes (3.1k)	CDN
gzip -6 (default)	2962 bytes (2.9k)	local copy
gzip -9	2962 bytes (2.9k)	local copy
cdnjs	2954 bytes (2.9k)	CDN
jsdelivr	2942 bytes (2.9k)	CDN
7zip -mx=9 -tgzip	2909 bytes (2.8k)	local copy
libdeflate -12	2909 bytes (2.8k)	local copy
pigz -11 -n	2909 bytes (2.8k)	local copy
kzip -s0 -rn -b0	2908 bytes (2.8k)	local copy
Zopfli	2906 bytes (2.8k)	local copy
zultra	2906 bytes (2.8k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/react/react-16.3.0.min.js (or via HTTPS)

You will automatically get the smallest React 16.3.0 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 36 bytes by using my React 16.3.0 Zopfli version instead of the best available CDN (1.24% smaller than jsdelivr, 2906 vs. 2942 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 --mls256 --bsr7 --lazy --ohh

(found April 9, 2018)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	256	--mls256
block splitting recursion	7	--bsr7
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

Verify file integrity

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

MD5:
curl --silent --compressed https://fb.me/react-16.3.0.min.js --location | md5sum
c3c8400137ef7922175e83cf0d326a0c -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.3.0.min.zopfli.js.gz | md5sum
c3c8400137ef7922175e83cf0d326a0c -

SHA1:
curl --silent --compressed https://fb.me/react-16.3.0.min.js --location | sha1sum
5b05b78d4f63364cd2e8dcc1d3b017afbc7e8250 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.3.0.min.zopfli.js.gz | sha1sum
5b05b78d4f63364cd2e8dcc1d3b017afbc7e8250 -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	3138 bytes	c3c8400137ef7922175e83cf0d326a0c	April 4, 2018 @ 06:37
cdnjs	2954 bytes	c3c8400137ef7922175e83cf0d326a0c	March 29, 2018 @ 23:24
jsdelivr	2942 bytes	c3c8400137ef7922175e83cf0d326a0c	April 23, 2018 @ 08:55

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
2906 bytes	-1 byte	zopfli --i100000 --mls256 --bsr7 --lazy --ohh	April 9, 2018 @ 10:06
2907 bytes	-1 byte	zopfli --i1000 --mls256 --bsr4 --lazy --ohh	April 9, 2018 @ 09:58
2908 bytes	–	zopfli --i100 --mls256 --bsr19 --lazy --ohh	April 9, 2018 @ 09:56

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

Most recent activity on July 20, 2020 @ 13:08.

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:
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	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
4	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
6	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
7	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
8	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
9	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
10	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
11	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
12	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
13	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
14	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
15	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
16	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
17	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
18	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
19	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
20	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
21	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
22	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
23	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
25	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
30	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906
40	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906	2906

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	2908 bytes	–	100%
1,000	2907 bytes	-1 byte	100%
10,000	2907 bytes	–	100%
100,000	2906 bytes	-1 byte	100%
1,000,000	2906 bytes	–	0.29%
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)	2908 bytes	+2 bytes (+0.07%)	–
1	2908 bytes	+2 bytes (+0.07%)	–
2	2917 bytes	+11 bytes (+0.38%)	+9 bytes
3	2943 bytes	+37 bytes (+1.27%)	+35 bytes
4	2973 bytes	+67 bytes (+2.31%)	+65 bytes
5	3003 bytes	+97 bytes (+3.34%)	+95 bytes
6	3038 bytes	+132 bytes (+4.54%)	+130 bytes
7	3079 bytes	+173 bytes (+5.95%)	+171 bytes
8	3115 bytes	+209 bytes (+7.19%)	+207 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 - for example, your browser actually supports it !

Algorithm	Program	Parameters	Size	Compared To Best Zopfli
Brotli (Wikipedia)	brotli	brotli -q 11	2588 bytes	-318 bytes (-10.94%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	2716 bytes	-190 bytes (-6.54%)
Zstandard (Wikipedia)	zstd	zstd -19	2939 bytes	+33 bytes (+1.14%)
LZMA2 (Wikipedia)	xz	xz -9	2988 bytes	+82 bytes (+2.82%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	3039 bytes	+133 bytes (+4.58%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	3126 bytes	+220 bytes (+7.57%)
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	3599 bytes	+693 bytes (+23.85%)

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.