Dojo 1.15.2 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 639053 bytes (624.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 167756 bytes (163.8k, 26%).

After GZIP compression these minified files vary in size:

gzip -6 (default)	56357 bytes (55.0k)	local copy
gzip -9	56287 bytes (55.0k)	local copy
libdeflate -12	53616 bytes (52.4k)	local copy
7zip -mx=9 -tgzip	53590 bytes (52.3k)	local copy
zultra	53523 bytes (52.3k)	local copy
kzip -s0 -rn -b1	53519 bytes (52.3k)	local copy
pigz -11 -n	53519 bytes (52.3k)	local copy
Zopfli	53425 bytes (52.2k)	local copy
Zopfli (defluff)	53424 bytes (52.2k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.15.2.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.15.2 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

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 --mls128 --bsr16 --lazy --ohh

(found February 24, 2020)

Description	Value	Parameter
iterations	1000000	--i1000000
maximum blocks	8	--mb8
maximum length score	128	--mls128
block splitting recursion	16	--bsr16
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 1 more byte (53424 bytes).

Download

Verify file integrity

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

MD5:
curl --silent --compressed https://download.dojotoolkit.org/release-1.15.2/dojo.js --location | md5sum
a1429839cfb5699eaf4ab68b1508d064 -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.15.2.min.zopfli.js.gz | md5sum
a1429839cfb5699eaf4ab68b1508d064 -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.15.2/dojo.js --location | sha1sum
208161ec06d2a587818cca66f4e3b78b28f18184 -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.15.2.min.zopfli.js.gz | sha1sum
208161ec06d2a587818cca66f4e3b78b28f18184 -

Other Versions

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

1.17.3, 1.17.2, 1.17.1, 1.17.0,
1.16.5, 1.16.4, 1.16.3, 1.16.2, 1.16.1, 1.16.0,
1.15.6, 1.15.5, 1.15.4, 1.15.3, 1.15.2, 1.15.1, 1.15.0,
1.14.9, 1.14.8, 1.14.7, 1.14.6, 1.14.5, 1.14.4, 1.14.3, 1.14.2, 1.14.1, 1.14.0,
1.13.10, 1.13.9, 1.13.8, 1.13.7, 1.13.6, 1.13.5, 1.13.4, 1.13.3, 1.13.2, 1.13.1, 1.13.0,
1.12.11, 1.12.10, 1.12.9, 1.12.8, 1.12.7, 1.12.6, 1.12.5, 1.12.4, 1.12.3, 1.12.2, 1.12.1,
1.11.13, 1.11.12, 1.11.11, 1.11.10, 1.11.9, 1.11.8, 1.11.7, 1.11.6, 1.11.5, 1.11.4, 1.11.3, 1.11.2, 1.11.1, 1.11.0,
1.10.10, 1.10.9, 1.10.8, 1.10.7, 1.10.6, 1.10.5, 1.10.4, 1.10.3, 1.10.2, 1.10.1, 1.10.0,
1.9.11, 1.9.10, 1.9.9, 1.9.8, 1.9.7, 1.9.6, 1.9.5, 1.9.4, 1.9.3, 1.9.2, 1.9.1, 1.9.0,
1.8.14, 1.8.13, 1.8.12, 1.8.11, 1.8.10, 1.8.9, 1.8.8, 1.8.7, 1.8.6, 1.8.5, 1.8.4, 1.8.3, 1.8.2, 1.8.1, 1.8.0,
1.7.12, 1.7.11, 1.7.10, 1.7.9, 1.7.8, 1.7.7, 1.7.6, 1.7.5, 1.7.4, 1.7.3, 1.7.2, 1.7.1, 1.7.0,
1.6.5, 1.6.4, 1.6.3, 1.6.2, 1.6.1, 1.6.0,
1.5.6, 1.5.5, 1.5.4, 1.5.3, 1.5.2, 1.5.1, 1.5.0,
1.4.8, 1.4.7, 1.4.6, 1.4.5, 1.4.4, 1.4.3, 1.4.2, 1.4.1, 1.4.0,
1.3.3, 1.3.2, 1.3.1, 1.3.0,
1.2.3, 1.2.2

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

Changelog

Best Zopfli parameters so far:

Size	Improvement	Parameters	Found
53425 bytes	-1 byte	zopfli --i1000000 --mls128 --bsr16 --lazy --ohh	February 24, 2020 @ 16:25
53426 bytes	-2 bytes	zopfli --i100000 --mls128 --bsr16 --lazy --ohh	February 19, 2020 @ 20:09
53428 bytes	-4 bytes	zopfli --i100000 --mls256 --bsr8 --lazy --ohh	February 19, 2020 @ 19:15
53432 bytes	-1 byte	zopfli --i10000 --mls128 --bsr16 --lazy --ohh	February 19, 2020 @ 18:40
53433 bytes	-7 bytes	zopfli --i10000 --mls256 --bsr8 --lazy --ohh	February 19, 2020 @ 18:22
53440 bytes	-1 byte	zopfli --i1000 --mls256 --bsr8 --lazy --ohh	February 19, 2020 @ 16:14
53441 bytes	-1 byte	zopfli --i1000 --mls32 --bsr20 --lazy --ohh	February 19, 2020 @ 15:02
53442 bytes	-1 byte	zopfli --i1000 --mls8192 --bsr20 --lazy --ohh	February 19, 2020 @ 14:01
53443 bytes	-1 byte	zopfli --i1000 --mls256 --bsr22 --lazy --ohh	February 19, 2020 @ 14:00
53444 bytes	–	zopfli --i100 --mls8192 --bsr9 --lazy --ohh	February 19, 2020 @ 13:53

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 @ 12:51.

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	53472	53433	53435	53434	53435	53435	53435	53432	53455	53447	53439	53437	53440	53472	53457
4	53465	53469	53439	53435	53438	53446	53435	53434	53443	53436	53456	53441	53439	53455	53439
6	53470	53481	53434	53439	53439	53448	53434	53443	53446	53443	53448	53457	53443	53452	53444
7	53465	53434	53438	53467	53433	53446	53441	53442	53443	53439	53450	53440	53449	53459	53440
8	53462	53468	53465	53467	53433	53443	53434	53428	53455	53444	53456	53435	53435	53451	53445
9	53447	53466	53433	53433	53433	53437	53435	53432	53443	53443	53456	53434	53434	53457	53443
10	53479	53434	53436	53470	53436	53434	53444	53433	53444	53444	53445	53441	53435	53451	53449
11	53432	53432	53436	53433	53435	53432	53434	53433	53443	53443	53444	53434	53453	53441	53444
12	53467	53470	53465	53440	53435	53433	53434	53432	53443	53444	53448	53441	53441	53448	53442
13	53467	53466	53433	53447	53444	53442	53432	53434	53444	53443	53444	53455	53439	53453	53448
14	53433	53476	53480	53470	53438	53437	53425	53436	53442	53446	53445	53440	53441	53451	53441
15	53465	53434	53426	53436	53447	53445	53425	53434	53443	53443	53449	53441	53435	53455	53446
16	53464	53468	53462	53475	53434	53449	53425	53444	53442	53444	53450	53449	53442	53453	53446
17	53470	53474	53476	53483	53433	53444	53432	53443	53444	53444	53444	53454	53453	53447	53442
18	53465	53433	53433	53468	53434	53433	53432	53442	53443	53444	53447	53439	53453	53447	53453
19	53467	53434	53433	53437	53438	53444	53432	53435	53442	53444	53448	53455	53434	53456	53442
20	53467	53471	53433	53435	53434	53448	53432	53442	53443	53444	53455	53439	53435	53453	53443
21	53468	53471	53433	53468	53439	53436	53432	53433	53443	53444	53447	53434	53457	53452	53442
22	53463	53474	53436	53434	53433	53455	53432	53434	53442	53442	53450	53434	53442	53449	53442
23	53433	53437	53460	53435	53435	53443	53432	53443	53444	53443	53451	53436	53439	53442	53450
25	53464	53464	53434	53433	53434	53435	53432	53443	53446	53445	53446	53446	53442	53452	53449
30	53464	53469	53433	53434	53438	53446	53432	53434	53443	53446	53447	53455	53440	53453	53441
40	53465	53469	53438	53435	53434	53444	53428	53427	53444	53443	53444	53456	53452	53453	53444

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	53444 bytes	–	100%
1,000	53440 bytes	-4 bytes	100%
10,000	53431 bytes	-9 bytes	100%
100,000	53426 bytes	-5 bytes	2.03%
1,000,000	53425 bytes	-1 byte	1.16%
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)	53601 bytes	+176 bytes (+0.33%)	+82 bytes
1	53519 bytes	+94 bytes (+0.18%)	–
2	53548 bytes	+123 bytes (+0.23%)	+29 bytes
3	53576 bytes	+151 bytes (+0.28%)	+57 bytes
4	53603 bytes	+178 bytes (+0.33%)	+84 bytes
5	53599 bytes	+174 bytes (+0.33%)	+80 bytes
6	53591 bytes	+166 bytes (+0.31%)	+72 bytes
7	53640 bytes	+215 bytes (+0.40%)	+121 bytes
8	53664 bytes	+239 bytes (+0.45%)	+145 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	39277 bytes	-14148 bytes (-26.48%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	46900 bytes	-6525 bytes (-12.21%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	47825 bytes	-5600 bytes (-10.48%)
Brotli (Wikipedia)	brotli	brotli -q 11	49281 bytes	-4144 bytes (-7.76%)
LZMA2 (Wikipedia)	xz	xz -9	50420 bytes	-3005 bytes (-5.62%)
Zstandard (Wikipedia)	zstd	zstd -19	51751 bytes	-1674 bytes (-3.13%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	52080 bytes	-1345 bytes (-2.52%)

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.