Choose a version:
26% The original file has 312045 bytes (304.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 81429 bytes (79.5k, 26%).

After GZIP compression these minified files vary in size:
Boot
  31846 bytes (31.1k)
CDN, direct link
Baidu
  27719 bytes (27.1k)
CDN, direct link
cdnjs
  27710 bytes (27.1k)
CDN, direct link
cdnhttps
  27693 bytes (27.0k)
CDN, direct link
gzip -6 (default)
  27611 bytes (27.0k)
local copy
gzip -9
  27576 bytes (26.9k)
local copy
7zip -mx=9 -tgzip
  26434 bytes (25.8k)
local copy
kzip -s0 -rn -b6
  26394 bytes (25.8k)
local copy
libdeflate -12
  26387 bytes (25.8k)
local copy
pigz -11 -n
  26367 bytes (25.7k)
local copy
Zopfli
  26261 bytes (25.6k)
local copy
Zopfli (defluff)
  26260 bytes (25.6k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.3.0.min.js

You will automatically get the smallest Dojo 1.3.0 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 1432 bytes by using my Dojo 1.3.0 Zopfli version instead of the best available CDN (5.45% smaller than cdnhttps, 26261 vs. 27693 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 --mls64 --bsr11 --lazy --ohh

(found December 1, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 64  --mls64
block splitting recursion 11  --bsr11
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 (26260 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://download.dojotoolkit.org/release-1.3.0/dojo.js --location | md5sum
b9f0fe08c2d8b5f00c3047274c5a445f  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.3.0.min.zopfli.js.gz | md5sum
b9f0fe08c2d8b5f00c3047274c5a445f  -

SHA1:
curl --silent --compressed http://download.dojotoolkit.org/release-1.3.0/dojo.js --location | sha1sum
a09b5851a0a3e9d81353745a4663741238ee1b84  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.3.0.min.zopfli.js.gz | sha1sum
a09b5851a0a3e9d81353745a4663741238ee1b84  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 31846 bytes b9f0fe08c2d8b5f00c3047274c5a445f March 19, 2015 @ 15:30
cdnjs 27710 bytes b9f0fe08c2d8b5f00c3047274c5a445f February 8, 2015 @ 14:45

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Baidu 27719 bytes 64dff5a67096bc892af3170c4f60de4b only whitespaces differ January 7, 2015 @ 10:16
cdnhttps 27693 bytes b8135437be82657eb080228412c4eefb < /*
< Copyright (c) 2004-2009, 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 a compiled version of Dojo, built for deployment [...]
< development. To get an editable version, please visit:
<
[...]
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:

1.12.2, 1.12.1,
1.11.4, 1.11.3, 1.11.2, 1.11.1, 1.11.0,
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,
1.8.12, 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,
1.7.10, 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
26261 bytes -3 bytes zopfli --i100000 --mls64 --bsr11 --lazy --ohh December 1, 2015 @ 13:44
26264 bytes -1 byte zopfli --i10000 --mls64 --bsr11 --lazy --ohh November 22, 2015 @ 22:23
26265 bytes -3 bytes zopfli --i10000 --mls128 --bsr25 --lazy --ohh October 14, 2015 @ 11:54
26268 bytes -2 bytes zopfli --i1000 --mls128 --bsr13 --lazy --ohh September 14, 2015 @ 22:36
26270 bytes -2 bytes zopfli --i1000 --mls64 --bsr16 --lazy --ohh September 14, 2015 @ 22:30
26272 bytes -1 byte zopfli --i1000 --mls64 --bsr10 --lazy --ohh September 14, 2015 @ 22:27
26273 bytes -1 byte zopfli --i1000 --mls512 --bsr8 --lazy --ohh September 11, 2015 @ 02:51
26274 bytes -1 byte zopfli --i1000 --mls512 --bsr9 --lazy --ohh September 11, 2015 @ 02:49
26275 bytes -7 bytes zopfli --i1000 --mls512 --bsr11 --lazy --ohh September 11, 2015 @ 02:49
26282 bytes zopfli --i100 --mls512 --bsr11 --lazy --ohh September 10, 2015 @ 14:58

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 @ 14:39.

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
26342 26335 26346 26326 26334 26356 26353 26348 26359 26350 26351 26345 26353 26353 26353
26348 26315 26348 26297 26310 26329 26286 26285 26346 26342 26343 26348 26351 26348 26348
26291 26284 26330 26339 26286 26285 26311 26349 26349 26349 26351 26346 26351 26347 26346
26335 26280 26328 26276 26273 26312 26351 26351 26346 26344 26346 26349 26351 26347 26348
26334 26323 26278 26295 26270 26295 26275 26282 26270 26345 26349 26348 26351 26345 26351
26282 26285 26293 26307 26270 26269 26310 26278 26269 26352 26347 26348 26273 26348 26347
26280 26279 26293 26288 26270 26266 26343 26280 26353 26352 26343 26347 26358 26351 26347
26291 26277 26288 26301 26316 26261 26273 26270 26267 26342 26342 26344 26273 26346 26351
26279 26296 26297 26297 26265 26272 26271 26347 26341 26342 26341 26343 26345 26350 26345
26315 26283 26324 26289 26266 26266 26265 26342 26344 26344 26341 26341 26350 26345 26344
26297 26313 26340 26300 26266 26267 26271 26272 26343 26346 26342 26346 26345 26348 26348
26285 26277 26281 26302 26280 26268 26266 26271 26347 26342 26342 26349 26350 26348 26346
26284 26296 26319 26301 26267 26261 26271 26280 26279 26343 26345 26348 26285 26345 26350
26294 26278 26306 26304 26271 26268 26353 26271 26269 26342 26341 26348 26347 26345 26346
26310 26293 26303 26301 26279 26272 26311 26347 26343 26343 26346 26349 26347 26349 26344
26298 26289 26327 26291 26269 26271 26267 26347 26273 26345 26348 26347 26295 26349 26348
26326 26316 26278 26304 26270 26310 26274 26269 26346 26345 26347 26348 26355 26348 26346
26283 26277 26291 26319 26319 26274 26268 26351 26346 26343 26344 26345 26345 26348 26348
26290 26279 26301 26337 26312 26291 26349 26349 26351 26351 26349 26348 26272 26344 26347
26296 26318 26344 26306 26268 26271 26267 26269 26270 26341 26343 26345 26351 26345 26346
26293 26279 26313 26281 26306 26268 26265 26347 26349 26351 26341 26347 26350 26347 26347
26284 26288 26282 26300 26267 26270 26269 26285 26287 26345 26342 26344 26273 26348 26345
26281 26310 26283 26321 26266 26269 26266 26271 26275 26343 26342 26344 26350 26350 26347

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 26278 bytes 100%
1,000 26268 bytes -10 bytes 100%
10,000 26264 bytes -4 bytes 100%
100,000 26261 bytes -3 bytes 0.58%
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
26396 bytes +135 bytes (+0.51%) +2 bytes
26396 bytes +135 bytes (+0.51%) +2 bytes
26415 bytes +154 bytes (+0.59%) +21 bytes
26397 bytes +136 bytes (+0.52%) +3 bytes
26434 bytes +173 bytes (+0.66%) +40 bytes
26413 bytes +152 bytes (+0.58%) +19 bytes
26394 bytes +133 bytes (+0.51%)
26407 bytes +146 bytes (+0.56%) +13 bytes
26452 bytes +191 bytes (+0.73%) +58 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 21252 bytes -5009 bytes (-19.07%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 23344 bytes -2917 bytes (-11.11%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 24220 bytes -2041 bytes (-7.77%)
Brotli (Wikipedia) brotli brotli -q 11 24430 bytes -1831 bytes (-6.97%)
LZMA2 (Wikipedia) xz xz -9 25288 bytes -973 bytes (-3.71%)
ZSTD (Wikipedia) zstd zstd -19 25891 bytes -370 bytes (-1.41%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 26026 bytes -235 bytes (-0.89%)

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 2017.
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