React 15.4.0 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 127469 bytes (124.5k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 21339 bytes (20.8k, 17%).

After GZIP compression these minified files vary in size:

Boot	8213 bytes (8.0k)	CDN
cdnjs	7359 bytes (7.2k)	CDN
gzip -6 (default)	7357 bytes (7.2k)	local copy
gzip -9	7336 bytes (7.2k)	local copy
jsdelivr	7333 bytes (7.2k)	CDN
unpkg	7333 bytes (7.2k)	CDN
libdeflate -12	7146 bytes (7.0k)	local copy
zultra	7144 bytes (7.0k)	local copy
7zip -mx=9 -tgzip	7116 bytes (6.9k)	local copy
pigz -11 -n	7062 bytes (6.9k)	local copy
kzip -s0 -rn -b3	7051 bytes (6.9k)	local copy
Zopfli	7028 bytes (6.9k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/react/react-15.4.0.min.js (or via HTTPS)

You will automatically get the smallest React 15.4.0 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 305 bytes by using my React 15.4.0 Zopfli version instead of the best available CDN (4.34% smaller than unpkg, 7028 vs. 7333 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 --mls64 --bsr18 --lazy --ohh

(found November 17, 2016)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	64	--mls64
block splitting recursion	18	--bsr18
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-15.4.0.min.js --location | md5sum
9a42408e46402432fa6a1c2771d35665 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-15.4.0.min.zopfli.js.gz | md5sum
9a42408e46402432fa6a1c2771d35665 -

SHA1:
curl --silent --compressed https://fb.me/react-15.4.0.min.js --location | sha1sum
481a85bc44a69396e506011f897988a5e4d22db8 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-15.4.0.min.zopfli.js.gz | sha1sum
481a85bc44a69396e506011f897988a5e4d22db8 -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	8213 bytes	9a42408e46402432fa6a1c2771d35665	November 17, 2016 @ 11:42
cdnjs	7359 bytes	9a42408e46402432fa6a1c2771d35665	(invalid)
jsdelivr	7333 bytes	9a42408e46402432fa6a1c2771d35665	(invalid)
unpkg	7333 bytes	9a42408e46402432fa6a1c2771d35665	November 17, 2016 @ 10:54

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
7028 bytes	-1 byte	zopfli --i100000 --mls64 --bsr18 --lazy --ohh	November 17, 2016 @ 11:36
7029 bytes	-1 byte	zopfli --i100000 --mls256 --bsr11 --lazy --ohh	November 17, 2016 @ 11:26
7030 bytes	-1 byte	zopfli --i10000 --mls128 --bsr9 --lazy --ohh	November 17, 2016 @ 11:13
7031 bytes	-3 bytes	zopfli --i1000 --mls128 --bsr6 --lazy --ohh	November 17, 2016 @ 11:12
7034 bytes	–	zopfli --i100 --mls128 --bsr6 --lazy --ohh	November 17, 2016 @ 11:07

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 @ 12:54.

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	7103	7103	7107	7062	7074	7069	7061	7135	7058	7073	7139	7063	7071	7079	7079
4	7061	7061	7064	7067	7066	7063	7066	7067	7075	7055	7082	7066	7052	7044	7043
6	7041	7032	7046	7044	7042	7033	7029	7042	7042	7040	7053	7055	7089	7089	7053
7	7038	7037	7059	7032	7038	7032	7033	7033	7048	7056	7049	7047	7132	7075	7075
8	7040	7040	7034	7034	7047	7034	7058	7043	7052	7059	7053	7054	7131	7078	7079
9	7042	7042	7035	7033	7038	7028	7029	7035	7031	7052	7056	7037	7137	7083	7036
10	7035	7067	7036	7037	7034	7031	7075	7075	7066	7053	7054	7057	7055	7082	7090
11	7039	7043	7036	7035	7035	7033	7028	7029	7033	7028	7033	7031	7131	7044	7079
12	7038	7036	7035	7054	7054	7047	7029	7035	7049	7049	7052	7042	7131	7051	7082
13	7038	7042	7056	7033	7029	7029	7033	7033	7028	7028	7053	7053	7049	7061	7058
14	7042	7038	7057	7032	7039	7033	7028	7033	7033	7054	7052	7033	7053	7090	7043
15	7037	7036	7059	7034	7032	7031	7033	7033	7054	7058	7052	7054	7131	7040	7041
16	7036	7037	7039	7038	7040	7033	7033	7040	7042	7053	7053	7132	7131	7061	7056
17	7040	7038	7036	7033	7038	7032	7028	7035	7082	7053	7136	7056	7137	7083	7053
18	7037	7037	7036	7032	7041	7028	7028	7033	7032	7031	7049	7056	7137	7083	7083
19	7038	7037	7038	7038	7041	7033	7033	7033	7028	7054	7052	7043	7132	7040	7040
20	7039	7037	7038	7032	7033	7031	7028	7033	7033	7028	7054	7045	7050	7089	7053
21	7038	7041	7036	7038	7041	7031	7028	7035	7028	7054	7048	7053	7053	7087	7059
22	7042	7039	7038	7038	7032	7032	7033	7035	7072	7054	7053	7053	7137	7039	7041
23	7039	7039	7037	7034	7033	7034	7036	7036	7032	7032	7033	7037	7132	7040	7040
25	7037	7033	7034	7038	7041	7033	7033	7033	7029	7028	7055	7032	7137	7080	7053
30	7036	7040	7035	7034	7040	7034	7033	7036	7029	7029	7136	7033	7053	7084	7053
40	7040	7039	7034	7032	7041	7031	7033	7033	7032	7032	7053	7131	7132	7090	7055

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	7034 bytes	–	100%
1,000	7031 bytes	-3 bytes	100%
10,000	7030 bytes	-1 byte	100%
100,000	7028 bytes	-2 bytes	6.96%
1,000,000	7028 bytes	–	4.35%
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)	7144 bytes	+116 bytes (+1.65%)	+93 bytes
1	7144 bytes	+116 bytes (+1.65%)	+93 bytes
2	7135 bytes	+107 bytes (+1.52%)	+84 bytes
3	7051 bytes	+23 bytes (+0.33%)	–
4	7072 bytes	+44 bytes (+0.63%)	+21 bytes
5	7103 bytes	+75 bytes (+1.07%)	+52 bytes
6	7136 bytes	+108 bytes (+1.54%)	+85 bytes
7	7173 bytes	+145 bytes (+2.06%)	+122 bytes
8	7197 bytes	+169 bytes (+2.40%)	+146 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
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	6425 bytes	-603 bytes (-8.58%)
Brotli (Wikipedia)	brotli	brotli -q 11	6487 bytes	-541 bytes (-7.70%)
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	6872 bytes	-156 bytes (-2.22%)
LZMA2 (Wikipedia)	xz	xz -9	6940 bytes	-88 bytes (-1.25%)
Zstandard (Wikipedia)	zstd	zstd -19	7077 bytes	+49 bytes (+0.70%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	7104 bytes	+76 bytes (+1.08%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	7212 bytes	+184 bytes (+2.62%)

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.