Choose a version:
26% The original file has 602290 bytes (588.2k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 157281 bytes (153.6k, 26%).

After GZIP compression these minified files vary in size:
Boot
  62403 bytes (60.9k)
CDN
cdnhttps
  54188 bytes (52.9k)
CDN
cdnjs
  54106 bytes (52.8k)
CDN
gzip -6 (default)
  53869 bytes (52.6k)
local copy
gzip -9
  53805 bytes (52.5k)
local copy
7zip -mx=9 -tgzip
  51208 bytes (50.0k)
local copy
libdeflate -12
  51181 bytes (50.0k)
local copy
kzip -s0 -rn -b1
  51131 bytes (49.9k)
local copy
pigz -11 -n
  51118 bytes (49.9k)
local copy
Zopfli
  51017 bytes (49.8k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.8.4.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.8.4 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 3089 bytes by using my Dojo 1.8.4 Zopfli version instead of the best available CDN (6.05% smaller than cdnjs, 51017 vs. 54106 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 --mls4 --bsr12 --lazy --ohh

(found December 3, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 4  --mls4
block splitting recursion 12  --bsr12
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

Verify file integrity

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

MD5:
curl --silent --compressed https://download.dojotoolkit.org/release-1.8.4/dojo.js --location | md5sum
43bd8d9040fd345651443863383f75a8  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.8.4.min.zopfli.js.gz | md5sum
43bd8d9040fd345651443863383f75a8  -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.8.4/dojo.js --location | sha1sum
f29f92adddd622765f704b2133a4693865f1e850  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.8.4.min.zopfli.js.gz | sha1sum
f29f92adddd622765f704b2133a4693865f1e850  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 62403 bytes 43bd8d9040fd345651443863383f75a8 March 19, 2015 @ 15:39
cdnjs 54106 bytes 43bd8d9040fd345651443863383f75a8 February 8, 2015 @ 14:45

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
cdnhttps 54188 bytes ddb764c32c621462c7bb09121b0c9abe < /*
< Copyright (c) 2004-2012, 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

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
51017 bytes -1 byte zopfli --i100000 --mls4 --bsr12 --lazy --ohh December 3, 2015 @ 15:49
51018 bytes -1 byte zopfli --i100000 --mls16384 --bsr25 --lazy --ohh December 3, 2015 @ 14:17
51019 bytes -4 bytes zopfli --i100000 --mls4 --bsr13 --lazy --ohh December 3, 2015 @ 12:03
51023 bytes -2 bytes zopfli --i10000 --mls16384 --bsr25 --lazy --ohh October 13, 2015 @ 22:51
51025 bytes -2 bytes zopfli --i1000 --mls16384 --bsr25 --lazy --ohh September 23, 2015 @ 03:58
51027 bytes -2 bytes zopfli --i1000 --mls16 --bsr11 --lazy --ohh September 19, 2015 @ 14:02
51029 bytes -1 byte zopfli --i1000 --mls64 --bsr14 --lazy --ohh September 12, 2015 @ 16:29
51030 bytes -3 bytes zopfli --i1000 --mls1024 --bsr6 --lazy --ohh September 10, 2015 @ 20:28
51033 bytes -4 bytes zopfli --i1000 --mls512 --bsr10 --lazy --ohh September 10, 2015 @ 20:20
51037 bytes zopfli --i100 --mls512 --bsr10 --lazy --ohh September 10, 2015 @ 15:01

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

Most recent activity on June 16, 2016 @ 14:37.

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
51031 51030 51033 51035 51033 51029 51038 51030 51035 51032 51031 51052 51058 51046 51029
51038 51029 51030 51020 51034 51034 51033 51041 51031 51039 51039 51042 51037 51040 51035
51027 51036 51027 51026 51030 51042 51033 51037 51032 51027 51047 51046 51051 51036 51033
51027 51051 51050 51053 51029 51049 51033 51028 51033 51047 51037 51043 51057 51029 51035
51030 51029 51033 51020 51028 51044 51032 51035 51031 51042 51052 51053 51055 51040 51033
51029 51035 51027 51037 51028 51033 51035 51038 51040 51040 51044 51048 51048 51044 51032
51023 51027 51048 51049 51029 51029 51032 51032 51028 51028 51031 51049 51051 51043 51032
51027 51025 51056 51020 51029 51028 51033 51031 51027 51034 51044 51048 51034 51037 51053
51027 51017 51050 51029 51034 51031 51036 51032 51033 51046 51038 51048 51052 51027 51032
51037 51019 51029 51020 51028 51032 51033 51033 51032 51036 51029 51048 51047 51034 51032
51027 51052 51050 51054 51028 51026 51037 51033 51039 51046 51028 51048 51049 51035 51033
51028 51026 51027 51052 51028 51048 51033 51033 51032 51051 51039 51048 51034 51033 51032
51027 51025 51025 51019 51028 51033 51033 51032 51032 51045 51029 51048 51054 51037 51032
51028 51029 51026 51055 51028 51047 51032 51031 51037 51034 51044 51048 51054 51031 51033
51025 51027 51030 51029 51034 51033 51034 51032 51031 51037 51049 51048 51050 51037 51032
51029 51030 51029 51051 51028 51025 51032 51032 51033 51040 51038 51047 51048 51032 51032
51028 51019 51024 51027 51028 51033 51032 51029 51044 51038 51044 51048 51051 51037 51032
51026 51029 51033 51047 51028 51033 51032 51030 51033 51038 51029 51048 51052 51036 51032
51020 51027 51033 51026 51029 51025 51032 51032 51033 51035 51044 51049 51052 51034 51033
51023 51029 51029 51020 51030 51049 51032 51028 51032 51045 51042 51045 51056 51031 51032
51034 51025 51053 51054 51030 51033 51035 51033 51032 51047 51050 51048 51054 51018 51032
51024 51025 51029 51027 51030 51037 51033 51034 51027 51046 51051 51048 51055 51033 51034
51026 51029 51026 51026 51028 51033 51035 51032 51029 51044 51048 51045 51049 51032 51033

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 51032 bytes 100%
1,000 51025 bytes -7 bytes 100%
10,000 51023 bytes -2 bytes 100%
100,000 51017 bytes -6 bytes 3.77%
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
51191 bytes +174 bytes (+0.34%) +60 bytes
51131 bytes +114 bytes (+0.22%)
51149 bytes +132 bytes (+0.26%) +18 bytes
51190 bytes +173 bytes (+0.34%) +59 bytes
51220 bytes +203 bytes (+0.40%) +89 bytes
51243 bytes +226 bytes (+0.44%) +112 bytes
51256 bytes +239 bytes (+0.47%) +125 bytes
51281 bytes +264 bytes (+0.52%) +150 bytes
51284 bytes +267 bytes (+0.52%) +153 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 37524 bytes -13493 bytes (-26.45%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 44393 bytes -6624 bytes (-12.98%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 45701 bytes -5316 bytes (-10.42%)
Brotli (Wikipedia) brotli brotli -q 11 46876 bytes -4141 bytes (-8.12%)
LZMA2 (Wikipedia) xz xz -9 47960 bytes -3057 bytes (-5.99%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 49243 bytes -1774 bytes (-3.48%)
Zstandard (Wikipedia) zstd zstd -19 49403 bytes -1614 bytes (-3.16%)

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