React 16.4.1 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 59086 bytes (57.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 7217 bytes (7.0k, 12%).

After GZIP compression these minified files vary in size:

gzip -9	3070 bytes (3.0k)	local copy
gzip -6 (default)	3069 bytes (3.0k)	local copy
Boot	3053 bytes (3.0k)	CDN
cdnjs	3053 bytes (3.0k)	CDN
jsdelivr	3049 bytes (3.0k)	CDN
libdeflate -12	3011 bytes (2.9k)	local copy
pigz -11 -n	3011 bytes (2.9k)	local copy
kzip -s0 -rn -b1	3009 bytes (2.9k)	local copy
7zip -mx=9 -tgzip	3008 bytes (2.9k)	local copy
zultra	3008 bytes (2.9k)	local copy
Zopfli	3007 bytes (2.9k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/react/react-16.4.1.min.js (or via HTTPS)

You will automatically get the smallest React 16.4.1 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 42 bytes by using my React 16.4.1 Zopfli version instead of the best available CDN (1.40% smaller than jsdelivr, 3007 vs. 3049 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 --i1000 --mb8 --mls8 --bsr2 --lazy --ohh

(found June 14, 2018)

Description	Value	Parameter
iterations	1000	--i1000
maximum blocks	8	--mb8
maximum length score	8	--mls8
block splitting recursion	2	--bsr2
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-16.4.1.min.js --location | md5sum
1a54709f250a912bd6a274b3096329cd -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.4.1.min.zopfli.js.gz | md5sum
1a54709f250a912bd6a274b3096329cd -

SHA1:
curl --silent --compressed https://fb.me/react-16.4.1.min.js --location | sha1sum
e43b6d17ec0ae9f6e1695aadbc9f48aaa4417066 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.4.1.min.zopfli.js.gz | sha1sum
e43b6d17ec0ae9f6e1695aadbc9f48aaa4417066 -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	3053 bytes	1a54709f250a912bd6a274b3096329cd	June 13, 2018 @ 19:00
cdnjs	3053 bytes	1a54709f250a912bd6a274b3096329cd	June 13, 2018 @ 19:00
jsdelivr	3049 bytes	1a54709f250a912bd6a274b3096329cd	June 14, 2018 @ 13:36

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
3007 bytes	-1 byte	zopfli --i1000 --mls8 --bsr2 --lazy --ohh	June 14, 2018 @ 13:53
3008 bytes	–	zopfli --i100 --mls8192 --bsr15 --lazy --ohh	June 14, 2018 @ 13:38

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 @ 12:47.

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	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
4	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
6	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
7	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
8	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
9	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
10	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
11	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
12	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
13	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
14	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
15	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
16	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
17	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
18	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
19	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
20	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
21	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
22	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
23	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
25	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
30	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007
40	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007	3007

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	3008 bytes	–	100%
1,000	3007 bytes	-1 byte	100%
10,000	3007 bytes	–	100%
100,000	3007 bytes	–	100%
1,000,000	3007 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)	3009 bytes	+2 bytes (+0.07%)	–
1	3009 bytes	+2 bytes (+0.07%)	–
2	3024 bytes	+17 bytes (+0.57%)	+15 bytes
3	3044 bytes	+37 bytes (+1.23%)	+35 bytes
4	3077 bytes	+70 bytes (+2.33%)	+68 bytes
5	3106 bytes	+99 bytes (+3.29%)	+97 bytes
6	3151 bytes	+144 bytes (+4.79%)	+142 bytes
7	3187 bytes	+180 bytes (+5.99%)	+178 bytes
8	3224 bytes	+217 bytes (+7.22%)	+215 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	2665 bytes	-342 bytes (-11.37%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	2814 bytes	-193 bytes (-6.42%)
Zstandard (Wikipedia)	zstd	zstd -19	3047 bytes	+40 bytes (+1.33%)
LZMA2 (Wikipedia)	xz	xz -9	3088 bytes	+81 bytes (+2.69%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	3161 bytes	+154 bytes (+5.12%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	3293 bytes	+286 bytes (+9.51%)
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	3686 bytes	+679 bytes (+22.58%)

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.