Dojo 1.2.3 - as small as it gets (near-perfect GZIP compression)

Choose a version:

The original file has 276341 bytes (269.9k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 78603 bytes (76.8k, 28%).

After GZIP compression these minified files vary in size:

Baidu	26538 bytes (25.9k)	CDN
gzip -6 (default)	26441 bytes (25.8k)	local copy
gzip -9	26423 bytes (25.8k)	local copy
Sina	26388 bytes (25.8k)	CDN
7zip -mx=9 -tgzip	25296 bytes (24.7k)	local copy
kzip -s0 -rn -b3	25255 bytes (24.7k)	local copy
libdeflate -12	25244 bytes (24.7k)	local copy
zultra	25239 bytes (24.6k)	local copy
pigz -11 -n	25212 bytes (24.6k)	local copy
Zopfli	25116 bytes (24.5k)	local copy
Zopfli (defluff)	25115 bytes (24.5k)	local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.2.3.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.2.3 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 1272 bytes by using my Dojo 1.2.3 Zopfli version instead of the best available CDN (5.06% smaller than Sina, 25116 vs. 26388 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 --mls128 --bsr15 --lazy --ohh

(found March 2, 2020)

Description	Value	Parameter
iterations	1000000	--i1000000
maximum blocks	8	--mb8
maximum length score	128	--mls128
block splitting recursion	15	--bsr15
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 (25115 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-1.2.3/dojo.js --location | md5sum
4245b24f70c09cb1dc9085882c180858 -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.2.3.min.zopfli.js.gz | md5sum
4245b24f70c09cb1dc9085882c180858 -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.2.3/dojo.js --location | sha1sum
2ab48d45abe2f54cdda6ca32193b5ceb2b1bc25d -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.2.3.min.zopfli.js.gz | sha1sum
2ab48d45abe2f54cdda6ca32193b5ceb2b1bc25d -

These CDNs send you the original file:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Sina	26388 bytes	4245b24f70c09cb1dc9085882c180858	April 25, 2019 @ 14:07

And some CDNs send you a different file:

CDN	Size (compressed)	MD5 (uncompressed)	Comment / Diff	Timestamp
Baidu	26538 bytes	502ae72cf1c76d31787f4e7544cdea21	only whitespaces differ	January 7, 2015 @ 10:16

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
25116 bytes	-1 byte	zopfli --i1000000 --mls128 --bsr15 --lazy --ohh	March 2, 2020 @ 14:56
25117 bytes	-2 bytes	zopfli --i100000 --mls128 --bsr15 --lazy --ohh	February 2, 2016 @ 20:12
25119 bytes	-2 bytes	zopfli --i10000 --mls128 --bsr15 --lazy --ohh	February 2, 2016 @ 19:08
25121 bytes	-5 bytes	zopfli --i1000 --mls128 --bsr15 --lazy --ohh	February 2, 2016 @ 18:59
25126 bytes	-4 bytes	zopfli --i1000 --mls8 --bsr15 --lazy --ohh	February 2, 2016 @ 18:58
25130 bytes	–	zopfli --i100 --mls8 --bsr15 --lazy --ohh	February 2, 2016 @ 18:57

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 @ 12:54.

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	25183	25161	25183	25160	25169	25161	25205	25204	25207	25209	25207	25206	25175	25206	25197
4	25170	25149	25155	25153	25180	25163	25167	25197	25203	25209	25200	25207	25141	25211	25199
6	25201	25159	25154	25165	25220	25218	25220	25197	25206	25201	25201	25207	25205	25210	25202
7	25183	25167	25157	25175	25153	25220	25223	25196	25206	25199	25207	25207	25201	25201	25203
8	25176	25169	25168	25126	25172	25219	25224	25197	25207	25205	25201	25200	25206	25201	25205
9	25182	25165	25149	25151	25220	25204	25220	25196	25206	25202	25199	25203	25203	25202	25208
10	25167	25172	25166	25175	25168	25130	25198	25197	25206	25196	25204	25199	25149	25210	25201
11	25167	25174	25163	25172	25157	25197	25133	25197	25197	25199	25198	25207	25172	25209	25200
12	25165	25167	25150	25148	25171	25121	25171	25196	25198	25198	25199	25197	25163	25209	25205
13	25144	25134	25165	25151	25178	25155	25176	25213	25199	25204	25197	25199	25120	25213	25206
14	25172	25173	25163	25171	25164	25215	25211	25197	25205	25199	25199	25197	25151	25210	25202
15	25155	25164	25118	25167	25164	25122	25116	25197	25206	25197	25197	25199	25200	25201	25202
16	25175	25169	25172	25171	25179	25122	25174	25197	25206	25205	25205	25201	25155	25201	25204
17	25173	25141	25167	25152	25164	25222	25220	25196	25196	25200	25201	25207	25154	25201	25199
18	25153	25138	25148	25150	25185	25130	25200	25199	25199	25196	25199	25198	25199	25201	25201
19	25171	25169	25173	25170	25172	25155	25220	25220	25207	25205	25202	25201	25127	25201	25203
20	25176	25151	25129	25173	25171	25156	25219	25197	25207	25206	25201	25207	25177	25201	25202
21	25165	25166	25172	25168	25163	25212	25214	25197	25197	25196	25199	25203	25200	25209	25205
22	25181	25171	25171	25175	25153	25222	25220	25149	25206	25197	25197	25200	25200	25201	25205
23	25175	25167	25166	25166	25155	25195	25211	25154	25207	25198	25200	25205	25207	25200	25202
25	25161	25167	25150	25153	25168	25123	25216	25197	25206	25196	25200	25199	25206	25202	25202
30	25151	25154	25147	25148	25149	25197	25214	25196	25197	25197	25199	25206	25206	25200	25207
40	25155	25174	25162	25171	25172	25215	25212	25197	25206	25199	25198	25197	25152	25201	25205

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	25130 bytes	–	100%
1,000	25121 bytes	-9 bytes	100%
10,000	25119 bytes	-2 bytes	100%
100,000	25117 bytes	-2 bytes	2.03%
1,000,000	25116 bytes	-1 byte	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)	25261 bytes	+145 bytes (+0.58%)	+6 bytes
1	25262 bytes	+146 bytes (+0.58%)	+7 bytes
2	25276 bytes	+160 bytes (+0.64%)	+21 bytes
3	25255 bytes	+139 bytes (+0.55%)	–
4	25290 bytes	+174 bytes (+0.69%)	+35 bytes
5	25271 bytes	+155 bytes (+0.62%)	+16 bytes
6	25257 bytes	+141 bytes (+0.56%)	+2 bytes
7	25259 bytes	+143 bytes (+0.57%)	+4 bytes
8	25296 bytes	+180 bytes (+0.72%)	+41 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	20441 bytes	-4675 bytes (-18.61%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	22391 bytes	-2725 bytes (-10.85%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	23276 bytes	-1840 bytes (-7.33%)
Brotli (Wikipedia)	brotli	brotli -q 11	23326 bytes	-1790 bytes (-7.13%)
LZMA2 (Wikipedia)	xz	xz -9	24240 bytes	-876 bytes (-3.49%)
Zstandard (Wikipedia)	zstd	zstd -19	24855 bytes	-261 bytes (-1.04%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	24985 bytes	-131 bytes (-0.52%)

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.