Dojo 1.9.1 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 613070 bytes (598.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 159460 bytes (155.7k, 26%).

After GZIP compression these minified files vary in size:

Boot	63385 bytes (61.9k)	CDN
cdnjs	54929 bytes (53.6k)	CDN
gzip -6 (default)	54689 bytes (53.4k)	local copy
gzip -9	54634 bytes (53.4k)	local copy
jsdelivr	54603 bytes (53.3k)	CDN
7zip -mx=9 -tgzip	52042 bytes (50.8k)	local copy
libdeflate -12	52041 bytes (50.8k)	local copy
zultra	52017 bytes (50.8k)	local copy
pigz -11 -n	52000 bytes (50.8k)	local copy
kzip -s0 -rn -b1	51993 bytes (50.8k)	local copy
Zopfli	51826 bytes (50.6k)	local copy
Zopfli (defluff)	51825 bytes (50.6k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.9.1.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.9.1 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 2777 bytes by using my Dojo 1.9.1 Zopfli version instead of the best available CDN (5.36% smaller than jsdelivr, 51826 vs. 54603 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 --mls4 --bsr4 --lazy --ohh

(found January 30, 2020)

Description	Value	Parameter
iterations	1000000	--i1000000
maximum blocks	8	--mb8
maximum length score	4	--mls4
block splitting recursion	4	--bsr4
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 (51825 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-1.9.1/dojo.js --location | md5sum
67b90c46c842c4d23b095cedf6f80ad8 -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.9.1.min.zopfli.js.gz | md5sum
67b90c46c842c4d23b095cedf6f80ad8 -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.9.1/dojo.js --location | sha1sum
a2f2bc8c9b103e113506ad4774223eb5a02d1214 -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.9.1.min.zopfli.js.gz | sha1sum
a2f2bc8c9b103e113506ad4774223eb5a02d1214 -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	63385 bytes	67b90c46c842c4d23b095cedf6f80ad8	March 19, 2015 @ 15:42
cdnjs	54929 bytes	67b90c46c842c4d23b095cedf6f80ad8	February 8, 2015 @ 14:45
jsdelivr	54603 bytes	67b90c46c842c4d23b095cedf6f80ad8	August 7, 2014 @ 19:16

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

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
51826 bytes	-3 bytes	zopfli --i1000000 --mls4 --bsr4 --lazy --ohh	January 30, 2020 @ 21:13
51829 bytes	-1 byte	zopfli --i100000 --mls4 --bsr4 --lazy --ohh	December 3, 2015 @ 19:21
51830 bytes	-4 bytes	zopfli --i100000 --mls8 --bsr12 --lazy --ohh	December 3, 2015 @ 16:47
51834 bytes	-1 byte	zopfli --i10000 --mls8 --bsr12 --lazy --ohh	October 13, 2015 @ 18:25
51835 bytes	-2 bytes	zopfli --i10000 --mls8 --bsr30 --lazy --ohh	September 24, 2015 @ 14:13
51837 bytes	-1 byte	zopfli --i1000 --mls8 --bsr30 --lazy --ohh	September 24, 2015 @ 13:26
51838 bytes	-5 bytes	zopfli --i1000 --mls8 --bsr12 --lazy --ohh	September 19, 2015 @ 05:43
51843 bytes	–	zopfli --i100 --mls8 --bsr12 --lazy --ohh	September 18, 2015 @ 16:24

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	51909	51908	51908	51905	51908	51910	51907	51906	51916	51931	51926	51922	51922	51926	51946
4	51846	51826	51858	51910	51910	51907	51911	51908	51908	51912	51919	51917	51903	51904	51893
6	51860	51863	51852	51917	51906	51910	51909	51909	51907	51907	51920	51923	51911	51914	51903
7	51848	51903	51846	51908	51907	51906	51908	51909	51908	51917	51912	51916	51911	51904	51900
8	51856	51856	51909	51909	51901	51901	51909	51909	51917	51904	51903	51903	51911	51899	51914
9	51859	51855	51908	51909	51899	51900	51906	51907	51914	51918	51915	51918	51919	51895	51908
10	51857	51870	51843	51909	51907	51901	51906	51907	51909	51903	51904	51912	51910	51905	51904
11	51846	51854	51841	51915	51906	51901	51908	51911	51914	51906	51913	51918	51911	51915	51898
12	51858	51861	51830	51916	51901	51902	51908	51910	51909	51899	51903	51924	51912	51898	51899
13	51857	51846	51859	51908	51901	51901	51909	51910	51914	51913	51917	51917	51920	51903	51906
14	51857	51849	51908	51921	51905	51901	51908	51910	51911	51896	51910	51921	51911	51904	51898
15	51853	51860	51846	51907	51907	51902	51908	51910	51907	51899	51917	51919	51910	51895	51897
16	51853	51859	51844	51906	51902	51907	51911	51911	51911	51903	51914	51920	51919	51898	51905
17	51856	51858	51906	51921	51901	51906	51909	51901	51912	51906	51916	51917	51910	51896	51895
18	51857	51858	51918	51918	51902	51906	51908	51911	51911	51903	51909	51918	51925	51896	51898
19	51845	51865	51910	51917	51903	51901	51908	51909	51916	51916	51904	51901	51911	51898	51900
20	51855	51862	51910	51917	51903	51901	51908	51911	51906	51898	51912	51917	51910	51897	51900
21	51841	51857	51844	51907	51905	51901	51906	51909	51913	51897	51912	51917	51910	51900	51897
22	51849	51851	51906	51907	51902	51906	51908	51909	51912	51902	51903	51907	51910	51897	51903
23	51849	51860	51845	51917	51904	51908	51909	51907	51907	51903	51916	51919	51910	51903	51904
25	51853	51914	51908	51916	51900	51904	51908	51907	51912	51910	51912	51918	51919	51899	51899
30	51854	51856	51830	51907	51905	51901	51906	51909	51910	51916	51906	51908	51910	51901	51913
40	51842	51853	51847	51909	51900	51908	51908	51909	51908	51904	51920	51918	51913	51900	51906

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	51843 bytes	–	100%
1,000	51837 bytes	-6 bytes	100%
10,000	51834 bytes	-3 bytes	100%
100,000	51829 bytes	-5 bytes	0.87%
1,000,000	51826 bytes	-3 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)	52048 bytes	+222 bytes (+0.43%)	+55 bytes
1	51993 bytes	+167 bytes (+0.32%)	–
2	52005 bytes	+179 bytes (+0.35%)	+12 bytes
3	52047 bytes	+221 bytes (+0.43%)	+54 bytes
4	52070 bytes	+244 bytes (+0.47%)	+77 bytes
5	52086 bytes	+260 bytes (+0.50%)	+93 bytes
6	52128 bytes	+302 bytes (+0.58%)	+135 bytes
7	52137 bytes	+311 bytes (+0.60%)	+144 bytes
8	52143 bytes	+317 bytes (+0.61%)	+150 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	38015 bytes	-13811 bytes (-26.65%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	45087 bytes	-6739 bytes (-13.00%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	46481 bytes	-5345 bytes (-10.31%)
Brotli (Wikipedia)	brotli	brotli -q 11	47562 bytes	-4264 bytes (-8.23%)
LZMA2 (Wikipedia)	xz	xz -9	48700 bytes	-3126 bytes (-6.03%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	50085 bytes	-1741 bytes (-3.36%)
Zstandard (Wikipedia)	zstd	zstd -19	50171 bytes	-1655 bytes (-3.19%)

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.