React 16.3.2 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 56545 bytes (55.2k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 7164 bytes (7.0k, 13%).

After GZIP compression these minified files vary in size:

Boot	3243 bytes (3.2k)	CDN
gzip -6 (default)	3060 bytes (3.0k)	local copy
gzip -9	3059 bytes (3.0k)	local copy
cdnjs	3049 bytes (3.0k)	CDN
jsdelivr	3040 bytes (3.0k)	CDN
7zip -mx=9 -tgzip	3004 bytes (2.9k)	local copy
pigz -11 -n	3003 bytes (2.9k)	local copy
zultra	3002 bytes (2.9k)	local copy
libdeflate -12	3001 bytes (2.9k)	local copy
kzip -s0 -rn -b1	3000 bytes (2.9k)	local copy
Zopfli	3000 bytes (2.9k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/react/react-16.3.2.min.js (or via HTTPS)

You will automatically get the smallest React 16.3.2 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 40 bytes by using my React 16.3.2 Zopfli version instead of the best available CDN (1.33% smaller than jsdelivr, 3000 vs. 3040 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 --i100 --mb8 --mls4 --bsr21 --lazy --ohh

(found April 24, 2018)

Description	Value	Parameter
iterations	100	--i100
maximum blocks	8	--mb8
maximum length score	4	--mls4
block splitting recursion	21	--bsr21
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-16.3.2.min.js --location | md5sum
cdf9611df0cc6d0a0db5de1af4cf4697 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.3.2.min.zopfli.js.gz | md5sum
cdf9611df0cc6d0a0db5de1af4cf4697 -

SHA1:
curl --silent --compressed https://fb.me/react-16.3.2.min.js --location | sha1sum
0500803a819aa37ee24049ffb3a89445cda06c7b -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.3.2.min.zopfli.js.gz | sha1sum
0500803a819aa37ee24049ffb3a89445cda06c7b -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	3243 bytes	cdf9611df0cc6d0a0db5de1af4cf4697	April 18, 2018 @ 03:42
cdnjs	3049 bytes	cdf9611df0cc6d0a0db5de1af4cf4697	April 16, 2018 @ 18:57
jsdelivr	3040 bytes	cdf9611df0cc6d0a0db5de1af4cf4697	April 24, 2018 @ 11:56

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
3000 bytes	–	zopfli --i100 --mls4 --bsr21 --lazy --ohh	April 24, 2018 @ 11:59

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 @ 12:56.

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	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
4	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
6	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
7	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
8	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
9	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
10	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
11	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
12	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
13	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
14	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
15	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
16	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
17	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
18	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
19	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
20	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
21	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
22	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
23	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
25	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
30	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000
40	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000	3000

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	3000 bytes	–	100%
1,000	3000 bytes	–	100%
10,000	3000 bytes	–	100%
100,000	3000 bytes	–	100%
1,000,000	3000 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)	3000 bytes	– (0.00%)	–
1	3000 bytes	– (0.00%)	–
2	3015 bytes	+15 bytes (+0.50%)	+15 bytes
3	3036 bytes	+36 bytes (+1.20%)	+36 bytes
4	3071 bytes	+71 bytes (+2.37%)	+71 bytes
5	3099 bytes	+99 bytes (+3.30%)	+99 bytes
6	3145 bytes	+145 bytes (+4.83%)	+145 bytes
7	3183 bytes	+183 bytes (+6.10%)	+183 bytes
8	3221 bytes	+221 bytes (+7.37%)	+221 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	2662 bytes	-338 bytes (-11.27%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	2802 bytes	-198 bytes (-6.60%)
Zstandard (Wikipedia)	zstd	zstd -19	3035 bytes	+35 bytes (+1.17%)
LZMA2 (Wikipedia)	xz	xz -9	3084 bytes	+84 bytes (+2.80%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	3157 bytes	+157 bytes (+5.23%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	3280 bytes	+280 bytes (+9.33%)
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	3674 bytes	+674 bytes (+22.47%)

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.