React 16.14.0 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 105138 bytes (102.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 12463 bytes (12.2k, 12%).

After GZIP compression these minified files vary in size:

Boot	4919 bytes (4.8k)	CDN
cdnjs	4919 bytes (4.8k)	CDN
gzip -6 (default)	4919 bytes (4.8k)	local copy
gzip -9	4917 bytes (4.8k)	local copy
zultra	4819 bytes (4.7k)	local copy
kzip -s0 -rn -b0	4818 bytes (4.7k)	local copy
libdeflate -12	4817 bytes (4.7k)	local copy
pigz -11 -n	4817 bytes (4.7k)	local copy
7zip -mx=9 -tgzip	4816 bytes (4.7k)	local copy
Zopfli	4810 bytes (4.7k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/react/react-16.14.0.min.js (or via HTTPS)

You will automatically get the smallest React 16.14.0 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 109 bytes by using my React 16.14.0 Zopfli version instead of the best available CDN (2.27% smaller than cdnjs, 4810 vs. 4919 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 --mls2 --bsr20 --lazy --ohh

(found October 17, 2020)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	2	--mls2
block splitting recursion	20	--bsr20
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-16.14.0.min.js --location | md5sum
63d498e143f421cc44dfb64f22fef270 -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.14.0.min.zopfli.js.gz | md5sum
63d498e143f421cc44dfb64f22fef270 -

SHA1:
curl --silent --compressed https://fb.me/react-16.14.0.min.js --location | sha1sum
1b4c8b769c3094cf499b3e7072c3776ef39ed02d -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.14.0.min.zopfli.js.gz | sha1sum
1b4c8b769c3094cf499b3e7072c3776ef39ed02d -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	4919 bytes	63d498e143f421cc44dfb64f22fef270	October 15, 2020 @ 00:12
cdnjs	4919 bytes	63d498e143f421cc44dfb64f22fef270	October 15, 2020 @ 00:12

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
4810 bytes	-1 byte	zopfli --i100000 --mls2 --bsr20 --lazy --ohh	October 17, 2020 @ 09:25
4811 bytes	-1 byte	zopfli --i10000 --mls2 --bsr23 --lazy --ohh	October 16, 2020 @ 14:05
4812 bytes	-1 byte	zopfli --i1000 --mls32 --bsr19 --lazy --ohh	October 16, 2020 @ 13:57
4813 bytes	–	zopfli --i100 --mls64 --bsr19 --lazy --ohh	October 16, 2020 @ 13:51

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

Most recent activity on October 19, 2020 @ 21:38.

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	4814	4814	4814	4814	4813	4813	4814	4814	4814	4814	4814	4814	4812	4814	4814
4	4813	4813	4813	4813	4812	4813	4812	4812	4813	4814	4814	4814	4814	4816	4816
6	4810	4810	4812	4813	4812	4813	4812	4812	4814	4811	4814	4814	4811	4814	4814
7	4810	4810	4813	4813	4811	4814	4814	4813	4812	4814	4814	4814	4813	4812	4812
8	4810	4810	4812	4813	4814	4813	4814	4813	4812	4814	4814	4814	4813	4814	4814
9	4810	4810	4814	4813	4814	4811	4814	4813	4811	4814	4814	4814	4813	4814	4814
10	4813	4813	4812	4812	4814	4813	4814	4814	4812	4814	4814	4814	4811	4814	4814
11	4813	4813	4810	4812	4812	4810	4814	4814	4811	4811	4814	4814	4813	4814	4814
12	4813	4813	4813	4813	4814	4812	4814	4813	4814	4814	4814	4814	4813	4812	4812
13	4812	4812	4812	4812	4813	4812	4814	4815	4811	4814	4814	4814	4813	4814	4814
14	4813	4813	4812	4812	4812	4811	4814	4813	4815	4814	4814	4814	4814	4814	4814
15	4810	4810	4813	4811	4812	4813	4814	4814	4812	4813	4814	4814	4811	4813	4813
16	4810	4810	4813	4812	4814	4811	4814	4813	4814	4814	4814	4814	4811	4812	4812
17	4813	4813	4813	4812	4812	4812	4814	4814	4812	4814	4814	4814	4813	4812	4812
18	4813	4813	4813	4813	4811	4810	4812	4814	4814	4814	4814	4814	4811	4814	4814
19	4810	4810	4812	4811	4811	4811	4812	4814	4812	4814	4814	4814	4812	4814	4814
20	4810	4810	4814	4813	4812	4811	4814	4813	4811	4813	4814	4814	4812	4814	4814
21	4810	4810	4814	4813	4812	4811	4814	4814	4812	4814	4814	4814	4811	4812	4812
22	4813	4813	4813	4812	4812	4811	4814	4813	4812	4813	4814	4814	4813	4812	4812
23	4810	4810	4810	4812	4812	4813	4814	4813	4812	4814	4814	4814	4811	4813	4813
25	4813	4813	4813	4812	4814	4813	4814	4814	4812	4814	4814	4814	4812	4812	4812
30	4811	4811	4811	4812	4812	4810	4814	4814	4812	4814	4814	4814	4814	4814	4814
40	4812	4812	4812	4813	4813	4814	4814	4814	4812	4811	4814	4814	4812	4814	4814

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	4813 bytes	–	100%
1,000	4812 bytes	-1 byte	100%
10,000	4811 bytes	-1 byte	100%
100,000	4810 bytes	-1 byte	15.65%
1,000,000	4810 bytes	–	7.25%
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)	4818 bytes	+8 bytes (+0.17%)	–
1	4818 bytes	+8 bytes (+0.17%)	–
2	4824 bytes	+14 bytes (+0.29%)	+6 bytes
3	4862 bytes	+52 bytes (+1.08%)	+44 bytes
4	4885 bytes	+75 bytes (+1.56%)	+67 bytes
5	4902 bytes	+92 bytes (+1.91%)	+84 bytes
6	4929 bytes	+119 bytes (+2.47%)	+111 bytes
7	4962 bytes	+152 bytes (+3.16%)	+144 bytes
8	4999 bytes	+189 bytes (+3.93%)	+181 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	4336 bytes	-474 bytes (-9.85%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	4415 bytes	-395 bytes (-8.21%)
Zstandard (Wikipedia)	zstd	zstd -19	4813 bytes	+3 bytes (+0.06%)
LZMA2 (Wikipedia)	xz	xz -9	4840 bytes	+30 bytes (+0.62%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	4912 bytes	+102 bytes (+2.12%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	4937 bytes	+127 bytes (+2.64%)
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	5175 bytes	+365 bytes (+7.59%)

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 2026.
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.