Choose a version:
25% The original file has 524788 bytes (512.5k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 130679 bytes (127.6k, 25%).

After GZIP compression these minified files vary in size:
Boot
  52012 bytes (50.8k)
CDN
cdnhttps
  45452 bytes (44.4k)
CDN
Baidu
  45328 bytes (44.3k)
CDN
cdnjs
  45322 bytes (44.3k)
CDN
gzip -6 (default)
  45161 bytes (44.1k)
local copy
gzip -9
  45134 bytes (44.1k)
local copy
Yandex
  45128 bytes (44.1k)
CDN
7zip -mx=9 -tgzip
  43088 bytes (42.1k)
local copy
libdeflate -12
  43029 bytes (42.0k)
local copy
kzip -s0 -rn -b1
  43009 bytes (42.0k)
local copy
pigz -11 -n
  42972 bytes (42.0k)
local copy
Zopfli
  42920 bytes (41.9k)
local copy
Zopfli (defluff)
  42918 bytes (41.9k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.7.1.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.7.1 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 2208 bytes by using my Dojo 1.7.1 Zopfli version instead of the best available CDN (5.14% smaller than Yandex, 42920 vs. 45128 bytes):
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 --i100000 --mb8 --mls16 --bsr9 --lazy --ohh

(found February 27, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 16  --mls16
block splitting recursion 9  --bsr9
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 (42918 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://download.dojotoolkit.org/release-1.7.1/dojo.js --location | md5sum
9e07b21778e76fa6d9af8e53568bcd7f  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.7.1.min.zopfli.js.gz | md5sum
9e07b21778e76fa6d9af8e53568bcd7f  -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.7.1/dojo.js --location | sha1sum
5fb5fb0235a7ae48333d954b8e98df729c963aa8  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.7.1.min.zopfli.js.gz | sha1sum
5fb5fb0235a7ae48333d954b8e98df729c963aa8  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 52012 bytes 9e07b21778e76fa6d9af8e53568bcd7f March 19, 2015 @ 15:33
cdnjs 45322 bytes 9e07b21778e76fa6d9af8e53568bcd7f February 8, 2015 @ 14:45

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
cdnhttps 45452 bytes 1b3df8cecad3e2bf951ece9727b0fa8c < /*
< Copyright (c) 2004-2011, The Dojo Foundation All Rights R [...]
< Available via Academic Free License >= 2.1 OR the modifie [...]
< see: http://dojotoolkit.org/license for details
< */
<
< /*
< This is an optimized version of Dojo, built for deploymen [...]
< development. To get sources and documentation, please vis [...]
<
[...]
December 24, 2015 @ 07:33
Baidu 45328 bytes d45f42225ad109b7cd93d12adfa2e812 only whitespaces differ January 7, 2015 @ 10:16
Yandex 45128 bytes 4a02353e1888f684fc4e76149ced9837 < (function(_1,_2){var _3=function(){},_4=function(it){for(v [...]
> (function(_1,_2){var _3=function(){},_4=function(it){for(v [...]
June 20, 2013 @ 11:59

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

Other Versions

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

1.14.2, 1.14.1, 1.14.0,
1.13.3, 1.13.2, 1.13.1, 1.13.0,
1.12.4, 1.12.3, 1.12.2, 1.12.1,
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,
1.6.3, 1.6.2, 1.6.1, 1.6.0,
1.5.4, 1.5.3, 1.5.2, 1.5.1, 1.5.0,
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

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
42920 bytes -1 byte zopfli --i100000 --mls16 --bsr9 --lazy --ohh February 27, 2016 @ 21:11
42921 bytes -5 bytes zopfli --i10000 --mls256 --bsr20 --lazy --ohh December 2, 2015 @ 12:21
42926 bytes -1 byte zopfli --i10000 --mls8192 --bsr7 --lazy --ohh November 22, 2015 @ 22:23
42927 bytes -1 byte zopfli --i1000 --mls8192 --bsr30 --lazy --ohh September 24, 2015 @ 18:13
42928 bytes -1 byte zopfli --i1000 --mls8192 --bsr7 --lazy --ohh September 14, 2015 @ 15:32
42929 bytes -1 byte zopfli --i1000 --mls256 --bsr16 --lazy --ohh September 14, 2015 @ 15:32
42930 bytes -1 byte zopfli --i1000 --mls512 --bsr7 --lazy --ohh September 14, 2015 @ 15:31
42931 bytes -4 bytes zopfli --i1000 --mls512 --bsr6 --lazy --ohh September 10, 2015 @ 22:25
42935 bytes -1 byte zopfli --i1000 --mls512 --bsr4 --lazy --ohh September 10, 2015 @ 22:25
42936 bytes zopfli --i100 --mls512 --bsr9 --lazy --ohh September 10, 2015 @ 15:03

If there are multiple parameter sets yielding the same compressed size, only the first one found is shown.

Most recent activity on October 4, 2018 @ 12:48.

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 or 100,000.
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
42982 42975 42983 42933 42939 42932 42931 42931 42931 42931 42935 42935 42956 42949 42961
42964 42967 42927 42930 42923 42928 42928 42929 42934 42931 42951 42950 42949 42940 42927
42971 42940 42932 42930 42925 42935 42932 42927 42928 42932 42932 42928 42939 42945 42930
42961 42961 42945 42929 42937 42955 42934 42932 42929 42927 42933 42955 42926 42935 42945
42965 42961 42928 42947 42933 42943 42931 42927 42930 42943 42933 42953 42936 42940 42927
42979 42970 42944 42920 42932 42947 42929 42927 42930 42947 42933 42950 42944 42945 42928
42969 42924 42941 42933 42929 42942 42931 42936 42931 42926 42959 42945 42943 42943 42938
42965 42963 42947 42924 42925 42943 42946 42927 42928 42928 42932 42947 42946 42941 42934
42967 42961 42945 42930 42936 42943 42932 42926 42931 42921 42945 42945 42944 42934 42934
42967 42963 42931 42924 42926 42949 42948 42934 42930 42932 42944 42930 42944 42942 42934
42969 42961 42950 42924 42926 42950 42932 42927 42930 42947 42933 42954 42942 42941 42933
42980 42970 42941 42925 42925 42942 42941 42928 42930 42927 42955 42950 42939 42937 42943
42966 42964 42927 42925 42927 42942 42927 42926 42932 42947 42954 42931 42944 42928 42938
42969 42962 42944 42924 42933 42942 42933 42927 42933 42948 42933 42930 42945 42943 42932
42969 42961 42945 42929 42928 42944 42950 42928 42929 42943 42934 42951 42935 42945 42951
42968 42963 42943 42930 42929 42940 42951 42925 42931 42943 42934 42949 42943 42941 42926
42983 42961 42946 42924 42934 42942 42947 42921 42931 42925 42944 42953 42944 42936 42934
42969 42961 42949 42925 42933 42950 42943 42924 42928 42946 42947 42956 42943 42928 42933
42963 42962 42925 42927 42929 42942 42948 42923 42931 42951 42947 42953 42938 42934 42934
42962 42961 42934 42924 42926 42942 42947 42932 42929 42948 42947 42955 42954 42944 42942
42965 42963 42929 42929 42926 42942 42934 42930 42928 42952 42943 42945 42933 42942 42933
42968 42964 42928 42923 42936 42950 42930 42925 42931 42948 42953 42954 42927 42942 42933
42962 42964 42941 42943 42927 42942 42943 42925 42932 42943 42954 42945 42944 42933 42933

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 42934 bytes 100%
1,000 42927 bytes -7 bytes 100%
10,000 42921 bytes -6 bytes 100%
100,000 42920 bytes -1 byte 1.16%
1,000,000
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
43030 bytes +110 bytes (+0.26%) +21 bytes
43009 bytes +89 bytes (+0.21%)
43034 bytes +114 bytes (+0.27%) +25 bytes
43048 bytes +128 bytes (+0.30%) +39 bytes
43074 bytes +154 bytes (+0.36%) +65 bytes
43057 bytes +137 bytes (+0.32%) +48 bytes
43091 bytes +171 bytes (+0.40%) +82 bytes
43128 bytes +208 bytes (+0.48%) +119 bytes
43156 bytes +236 bytes (+0.55%) +147 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 - but your browser doesn't support it.
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 32270 bytes -10650 bytes (-24.81%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 37632 bytes -5288 bytes (-12.32%)
Brotli (Wikipedia) brotli brotli -q 11 39492 bytes -3428 bytes (-7.99%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 39524 bytes -3396 bytes (-7.91%)
LZMA2 (Wikipedia) xz xz -9 40504 bytes -2416 bytes (-5.63%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 41639 bytes -1281 bytes (-2.98%)
Zstandard (Wikipedia) zstd zstd -19 41680 bytes -1240 bytes (-2.89%)

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):


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 2018.
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