React 16.7.0 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 100355 bytes (98.0k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 11800 bytes (11.5k, 12%).

After GZIP compression these minified files vary in size:

gzip -6 (default)	4690 bytes (4.6k)	local copy
gzip -9	4686 bytes (4.6k)	local copy
Boot	4677 bytes (4.6k)	CDN
cdnjs	4677 bytes (4.6k)	CDN
jsdelivr	4670 bytes (4.6k)	CDN
zultra	4599 bytes (4.5k)	local copy
libdeflate -12	4597 bytes (4.5k)	local copy
7zip -mx=9 -tgzip	4595 bytes (4.5k)	local copy
kzip -s0 -rn -b0	4595 bytes (4.5k)	local copy
pigz -11 -n	4593 bytes (4.5k)	local copy
Zopfli	4589 bytes (4.5k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/react/react-16.7.0.min.js (or via HTTPS)

You will automatically get the smallest React 16.7.0 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 81 bytes by using my React 16.7.0 Zopfli version instead of the best available CDN (1.77% smaller than jsdelivr, 4589 vs. 4670 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 --i10000 --mb8 --mls32768 --bsr11 --lazy --ohh

(found August 7, 2019)

Description	Value	Parameter
iterations	10000	--i10000
maximum blocks	8	--mb8
maximum length score	32768	--mls32768
block splitting recursion	11	--bsr11
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-16.7.0.min.js --location | md5sum
6797a59ed573f8a4c1c74db6e354f2eb -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.7.0.min.zopfli.js.gz | md5sum
6797a59ed573f8a4c1c74db6e354f2eb -

SHA1:
curl --silent --compressed https://fb.me/react-16.7.0.min.js --location | sha1sum
46c8c78a0773d7210f28d97d340c91b3a7a187cb -
curl --silent --compressed https://minime.stephan-brumme.com/files/react/react-16.7.0.min.zopfli.js.gz | sha1sum
46c8c78a0773d7210f28d97d340c91b3a7a187cb -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	4677 bytes	6797a59ed573f8a4c1c74db6e354f2eb	December 20, 2018 @ 02:45
cdnjs	4677 bytes	6797a59ed573f8a4c1c74db6e354f2eb	December 20, 2018 @ 02:45
jsdelivr	4670 bytes	6797a59ed573f8a4c1c74db6e354f2eb	August 7, 2019 @ 19:05

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
4589 bytes	-1 byte	zopfli --i10000 --mls32768 --bsr11 --lazy --ohh	August 7, 2019 @ 17:47
4590 bytes	-2 bytes	zopfli --i1000 --mls4096 --bsr22 --lazy --ohh	August 7, 2019 @ 16:43
4592 bytes	-1 byte	zopfli --i1000 --mls512 --bsr8 --lazy --ohh	August 7, 2019 @ 16:43
4593 bytes	–	zopfli --i100 --mls1024 --bsr20 --lazy --ohh	August 7, 2019 @ 16:25

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 @ 12:52.

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	4593	4593	4594	4593	4594	4592	4595	4594	4592	4592	4592	4592	4594	4594	4594
4	4592	4592	4592	4592	4594	4594	4593	4594	4592	4592	4592	4593	4591	4589	4589
6	4594	4594	4592	4594	4594	4594	4593	4593	4592	4592	4592	4592	4594	4593	4593
7	4593	4593	4593	4594	4594	4594	4593	4592	4592	4592	4592	4592	4597	4597	4597
8	4593	4593	4594	4594	4594	4598	4594	4594	4592	4592	4592	4592	4590	4597	4597
9	4594	4594	4594	4594	4594	4594	4594	4594	4592	4592	4592	4593	4598	4598	4598
10	4594	4594	4593	4594	4594	4598	4594	4593	4592	4592	4592	4593	4594	4589	4589
11	4593	4593	4593	4596	4592	4594	4593	4592	4592	4592	4592	4593	4589	4589	4589
12	4593	4593	4593	4594	4594	4595	4593	4593	4592	4592	4592	4589	4594	4598	4598
13	4594	4594	4594	4594	4594	4594	4593	4592	4592	4592	4592	4593	4598	4594	4594
14	4594	4594	4594	4594	4594	4594	4594	4594	4592	4592	4592	4590	4594	4598	4598
15	4594	4594	4593	4594	4594	4594	4594	4594	4592	4592	4592	4592	4594	4598	4598
16	4594	4594	4594	4594	4594	4594	4594	4593	4592	4592	4592	4590	4598	4593	4593
17	4593	4593	4594	4593	4594	4594	4593	4593	4592	4592	4592	4593	4590	4594	4594
18	4594	4594	4593	4594	4594	4594	4594	4594	4592	4592	4592	4590	4594	4595	4595
19	4594	4594	4593	4594	4594	4594	4594	4593	4592	4592	4592	4593	4593	4593	4593
20	4594	4594	4593	4593	4594	4594	4593	4594	4592	4592	4592	4593	4598	4598	4598
21	4593	4593	4593	4594	4594	4594	4593	4593	4592	4592	4592	4593	4589	4589	4589
22	4593	4593	4593	4594	4594	4594	4593	4593	4592	4592	4592	4589	4591	4589	4589
23	4593	4593	4593	4594	4594	4594	4593	4593	4592	4592	4592	4593	4598	4598	4598
25	4594	4594	4593	4593	4595	4594	4594	4594	4592	4592	4592	4593	4598	4598	4598
30	4595	4595	4593	4596	4594	4597	4594	4595	4592	4592	4592	4589	4598	4598	4598
40	4593	4593	4594	4594	4594	4594	4594	4593	4592	4592	4592	4590	4598	4598	4598

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	4593 bytes	–	100%
1,000	4590 bytes	-3 bytes	100%
10,000	4589 bytes	-1 byte	100%
100,000	4589 bytes	–	4.35%
1,000,000	4589 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)	4595 bytes	+6 bytes (+0.13%)	–
1	4595 bytes	+6 bytes (+0.13%)	–
2	4607 bytes	+18 bytes (+0.39%)	+12 bytes
3	4639 bytes	+50 bytes (+1.09%)	+44 bytes
4	4663 bytes	+74 bytes (+1.61%)	+68 bytes
5	4697 bytes	+108 bytes (+2.35%)	+102 bytes
6	4724 bytes	+135 bytes (+2.94%)	+129 bytes
7	4757 bytes	+168 bytes (+3.66%)	+162 bytes
8	4787 bytes	+198 bytes (+4.31%)	+192 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	4126 bytes	-463 bytes (-10.09%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	4216 bytes	-373 bytes (-8.13%)
Zstandard (Wikipedia)	zstd	zstd -19	4579 bytes	-10 bytes (-0.22%)
LZMA2 (Wikipedia)	xz	xz -9	4632 bytes	+43 bytes (+0.94%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	4736 bytes	+147 bytes (+3.20%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	4740 bytes	+151 bytes (+3.29%)
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	5015 bytes	+426 bytes (+9.28%)

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.