lodash 4.13.1 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 515628 bytes (503.5k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 67961 bytes (66.4k, 13%).

After GZIP compression these minified files vary in size:

Boot	26755 bytes (26.1k)	CDN
cdnjs	23668 bytes (23.1k)	CDN
unpkg	22545 bytes (22.0k)	CDN
gzip -6 (default)	22524 bytes (22.0k)	local copy
gzip -9	22459 bytes (21.9k)	local copy
jsdelivr	22454 bytes (21.9k)	CDN
libdeflate -12	21790 bytes (21.3k)	local copy
7zip -mx=9 -tgzip	21732 bytes (21.2k)	local copy
zultra	21723 bytes (21.2k)	local copy
kzip -s0 -rn -b2	21715 bytes (21.2k)	local copy
pigz -11 -n	21694 bytes (21.2k)	local copy
Zopfli	21646 bytes (21.1k)	local copy
Zopfli (defluff)	21644 bytes (21.1k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/lodash/lodash-4.13.1.min.js (or via HTTPS)

You will automatically get the smallest lodash 4.13.1 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 808 bytes by using my lodash 4.13.1 Zopfli version instead of the best available CDN (3.73% smaller than jsdelivr, 21646 vs. 22454 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 --i1000000 --mb8 --mls8 --bsr21 --lazy --ohh

(found May 25, 2016)

Description	Value	Parameter
iterations	1000000	--i1000000
maximum blocks	8	--mb8
maximum length score	8	--mls8
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

Even Smaller Files Thanks To Defluff

Zopfli's output can be further optimized by the defluff tool.
In this particular case, defluff saves 2 more bytes (21644 bytes).

Download

Verify file integrity

After decompression, my uncompressed files are identical to the original ones:

MD5:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.13.1/dist/lodash.min.js --location | md5sum
b966383b651f746af67721cc41dc1da4 -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.13.1.min.zopfli.js.gz | md5sum
b966383b651f746af67721cc41dc1da4 -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.13.1/dist/lodash.min.js --location | sha1sum
95a05c6651976f5e50873c1bb1ac8c9d0362293b -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.13.1.min.zopfli.js.gz | sha1sum
95a05c6651976f5e50873c1bb1ac8c9d0362293b -

These CDNs send you the original file:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
unpkg	22545 bytes	b966383b651f746af67721cc41dc1da4	July 11, 2016 @ 16:45
jsdelivr	22454 bytes	b966383b651f746af67721cc41dc1da4	(invalid)

And some CDNs send you a different file:

CDN	Size (compressed)	MD5 (uncompressed)	Comment / Diff	Timestamp
Boot	26755 bytes	b9f2efc1470d5c7ce9eee9b951ab1539	< /** < * @license < * lodash lodash.com/license \| Underscore.js 1.8.3 undersc [...] < */ < ;(function(){function t(t,n){return t.set(n[0],n[1]),t}fun [...] < return t}function i(t,n){for(var r=-1,e=t?t.length:0;++r<e [...] < var u=-1,o=t?t.length:0;for(e&&o&&(r=t[++u]);++u<o;)r=n(r, [...] < return-1}function y(t,n,r,e){--r;for(var u=t.length;++r<u; [...] < })}function O(t){return function(n){return t(n)}}function [...] < }function C(t){var n=false;if(null!=t&&typeof t.toString!= [...] [...]	(invalid)
cdnjs	23668 bytes	b9f2efc1470d5c7ce9eee9b951ab1539	< /** < * @license < * lodash lodash.com/license \| Underscore.js 1.8.3 undersc [...] < */ < ;(function(){function t(t,n){return t.set(n[0],n[1]),t}fun [...] < return t}function i(t,n){for(var r=-1,e=t?t.length:0;++r<e [...] < var u=-1,o=t?t.length:0;for(e&&o&&(r=t[++u]);++u<o;)r=n(r, [...] < return-1}function y(t,n,r,e){--r;for(var u=t.length;++r<u; [...] < })}function O(t){return function(n){return t(n)}}function [...] < }function C(t){var n=false;if(null!=t&&typeof t.toString!= [...] [...]	(invalid)

Note: only the MD5 hashes are shown to keep things simple.

Other Versions

Available lodash versions at minime.stephan-brumme.com:

4.17.21, 4.17.20, 4.17.19, 4.17.18, 4.17.17, 4.17.16, 4.17.15, 4.17.14, 4.17.13, 4.17.12, 4.17.11, 4.17.10, 4.17.9, 4.17.5, 4.17.4, 4.17.3, 4.17.2, 4.17.1, 4.17.0, 4.16.6, 4.16.5, 4.16.4, 4.16.3, 4.16.2, 4.16.1, 4.16.0, 4.15.0, 4.14.2, 4.14.1, 4.14.0, 4.13.1, 4.13.0, 4.12.0, 4.11.2, 4.11.1, 4.11.0, 4.10.0,
4.9.0, 4.8.2, 4.8.1, 4.8.0, 4.7.0, 4.6.1, 4.6.0, 4.5.1, 4.5.0, 4.4.0, 4.3.0, 4.2.1, 4.2.0, 4.1.0, 4.0.1, 4.0.0

The project site contains an overview how well these versions were compressed.
Other interesting projects are AngularJS, BackboneJS, Bootstrap, D3, Dojo, Ember, jQuery, Knockout, React, Socket.IO, ThreeJS, UnderscoreJS and Vue.

Changelog

Best Zopfli parameters so far:

Size	Improvement	Parameters	Found
21646 bytes	-2 bytes	zopfli --i1000000 --mls8 --bsr21 --lazy --ohh	May 25, 2016 @ 22:51
21648 bytes	-1 byte	zopfli --i1000000 --mls4 --bsr18 --lazy --ohh	May 25, 2016 @ 19:21
21649 bytes	-1 byte	zopfli --i100000 --mls4 --bsr18 --lazy --ohh	May 25, 2016 @ 06:43
21650 bytes	-2 bytes	zopfli --i100000 --mls4 --bsr14 --lazy --ohh	May 25, 2016 @ 05:23
21652 bytes	-3 bytes	zopfli --i10000 --mls4 --bsr18 --lazy --ohh	May 25, 2016 @ 04:48
21655 bytes	-1 byte	zopfli --i1000 --mls4 --bsr14 --lazy --ohh	May 25, 2016 @ 04:47
21656 bytes	-2 bytes	zopfli --i1000 --mls4 --bsr18 --lazy --ohh	May 25, 2016 @ 04:46
21658 bytes	-8 bytes	zopfli --i1000 --mls32 --bsr18 --lazy --ohh	May 25, 2016 @ 04:46
21666 bytes	–	zopfli --i100 --mls32 --bsr17 --lazy --ohh	May 25, 2016 @ 04:42

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 @ 12:49.

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	21682	21682	21699	21697	21699	21698	21697	21700	21699	21702	21698	21695	21696	21693	21695
4	21662	21669	21667	21668	21654	21662	21681	21668	21668	21668	21667	21671	21673	21668	21667
6	21661	21667	21666	21667	21662	21660	21669	21666	21673	21673	21675	21669	21670	21670	21674
7	21657	21661	21653	21667	21653	21678	21667	21661	21663	21675	21663	21670	21665	21685	21665
8	21659	21666	21668	21668	21665	21671	21668	21660	21663	21674	21668	21670	21666	21678	21666
9	21663	21684	21650	21659	21660	21662	21665	21668	21661	21674	21663	21669	21665	21674	21669
10	21663	21650	21650	21663	21654	21661	21667	21662	21671	21665	21666	21664	21671	21685	21664
11	21658	21659	21672	21672	21671	21671	21666	21662	21663	21670	21663	21669	21665	21677	21687
12	21654	21660	21657	21667	21668	21667	21663	21659	21668	21675	21673	21669	21669	21684	21670
13	21655	21661	21659	21664	21669	21664	21676	21663	21663	21665	21663	21671	21667	21661	21677
14	21655	21650	21661	21671	21655	21663	21673	21660	21660	21666	21660	21670	21666	21666	21675
15	21655	21661	21657	21669	21655	21660	21666	21663	21663	21661	21663	21669	21666	21675	21671
16	21658	21658	21654	21669	21665	21664	21675	21662	21669	21667	21664	21670	21667	21678	21672
17	21658	21658	21661	21674	21654	21662	21666	21656	21669	21675	21669	21668	21664	21668	21667
18	21661	21648	21662	21667	21653	21664	21672	21662	21672	21666	21666	21668	21668	21660	21669
19	21655	21654	21653	21673	21663	21663	21672	21667	21666	21663	21664	21669	21664	21679	21670
20	21665	21659	21665	21670	21659	21654	21670	21660	21665	21672	21664	21670	21671	21661	21671
21	21654	21653	21646	21667	21655	21651	21672	21665	21658	21665	21662	21672	21663	21662	21669
22	21655	21668	21666	21663	21668	21665	21671	21667	21662	21674	21666	21670	21666	21678	21665
23	21663	21661	21661	21669	21671	21664	21672	21658	21669	21665	21662	21671	21664	21673	21664
25	21655	21655	21663	21667	21664	21664	21672	21666	21668	21665	21669	21671	21663	21660	21673
30	21662	21667	21653	21668	21668	21670	21662	21667	21665	21665	21664	21671	21665	21661	21665
40	21656	21662	21655	21664	21653	21663	21672	21666	21663	21675	21669	21672	21663	21676	21672

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	21666 bytes	–	100%
1,000	21655 bytes	-11 bytes	100%
10,000	21652 bytes	-3 bytes	100%
100,000	21649 bytes	-3 bytes	2.03%
1,000,000	21646 bytes	-3 bytes	0.58%
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)	21729 bytes	+83 bytes (+0.38%)	+14 bytes
1	21777 bytes	+131 bytes (+0.61%)	+62 bytes
2	21715 bytes	+69 bytes (+0.32%)	–
3	21729 bytes	+83 bytes (+0.38%)	+14 bytes
4	21717 bytes	+71 bytes (+0.33%)	+2 bytes
5	21734 bytes	+88 bytes (+0.41%)	+19 bytes
6	21752 bytes	+106 bytes (+0.49%)	+37 bytes
7	21779 bytes	+133 bytes (+0.61%)	+64 bytes
8	21804 bytes	+158 bytes (+0.73%)	+89 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
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	18307 bytes	-3339 bytes (-15.43%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	18613 bytes	-3033 bytes (-14.01%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	18982 bytes	-2664 bytes (-12.31%)
Brotli (Wikipedia)	brotli	brotli -q 11	20346 bytes	-1300 bytes (-6.01%)
LZMA2 (Wikipedia)	xz	xz -9	20820 bytes	-826 bytes (-3.82%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	20894 bytes	-752 bytes (-3.47%)
Zstandard (Wikipedia)	zstd	zstd -19	21499 bytes	-147 bytes (-0.68%)

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 2025.
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.