Choose a version:
26% The original file has 611423 bytes (597.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 159534 bytes (155.8k, 26%).

After GZIP compression these minified files vary in size:
gzip -6 (default)
  54035 bytes (52.8k)
local copy
gzip -9
  53987 bytes (52.7k)
local copy
7zip -mx=9 -tgzip
  51404 bytes (50.2k)
local copy
libdeflate -12
  51353 bytes (50.1k)
local copy
kzip -s0 -rn -b1
  51317 bytes (50.1k)
local copy
pigz -11 -n
  51315 bytes (50.1k)
local copy
Zopfli
  51223 bytes (50.0k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.8.12.min.js

You will automatically get the smallest Dojo 1.8.12 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

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 --mls2 --bsr11 --lazy --ohh

(found June 10, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 2  --mls2
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

Verify file integrity

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

MD5:
curl --silent --compressed http://download.dojotoolkit.org/release-1.8.12/dojo.js --location | md5sum
676631e137350193ccb0ed899f931a1c  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.8.12.min.zopfli.js.gz | md5sum
676631e137350193ccb0ed899f931a1c  -

SHA1:
curl --silent --compressed http://download.dojotoolkit.org/release-1.8.12/dojo.js --location | sha1sum
d70a5728ad9dbee0688117f23b3ed5d07ce361ce  -
curl --silent --compressed http://minime.stephan-brumme.com/files/dojo/dojo-1.8.12.min.zopfli.js.gz | sha1sum
d70a5728ad9dbee0688117f23b3ed5d07ce361ce  -

Other Versions

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

1.13.0,
1.12.3, 1.12.2, 1.12.1,
1.11.5, 1.11.4, 1.11.3, 1.11.2, 1.11.1, 1.11.0,
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,
1.8.12, 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
51223 bytes -5 bytes zopfli --i100000 --mls2 --bsr11 --lazy --ohh June 10, 2016 @ 14:35
51228 bytes -1 byte zopfli --i10000 --mls2 --bsr11 --lazy --ohh June 10, 2016 @ 13:22
51229 bytes -2 bytes zopfli --i100000 --mls2 --bsr19 --lazy --ohh June 10, 2016 @ 09:48
51231 bytes -5 bytes zopfli --i10000 --mls2 --bsr19 --lazy --ohh June 10, 2016 @ 08:47
51236 bytes -4 bytes zopfli --i1000 --mls2 --bsr19 --lazy --ohh June 10, 2016 @ 08:41
51240 bytes zopfli --i100 --mls2 --bsr19 --lazy --ohh June 9, 2016 @ 18:18

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, 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
51234 51235 51235 51236 51234 51241 51236 51240 51246 51253 51255 51252 51257 51260 51266
51240 51232 51272 51247 51234 51236 51236 51237 51237 51249 51237 51245 51247 51246 51239
51237 51257 51237 51251 51237 51233 51232 51237 51237 51245 51237 51244 51244 51237 51243
51234 51268 51256 51239 51235 51237 51238 51248 51237 51233 51236 51247 51244 51241 51242
51275 51275 51248 51250 51238 51233 51233 51237 51238 51239 51238 51242 51240 51244 51244
51230 51238 51250 51244 51233 51234 51234 51233 51237 51246 51253 51249 51242 51242 51251
51239 51235 51237 51276 51235 51237 51234 51239 51237 51236 51237 51247 51243 51233 51250
51223 51232 51249 51254 51235 51236 51237 51236 51243 51246 51239 51243 51242 51248 51249
51231 51268 51270 51249 51233 51233 51236 51237 51237 51246 51239 51247 51244 51251 51264
51270 51230 51268 51238 51236 51237 51233 51236 51242 51241 51238 51244 51243 51243 51256
51270 51245 51272 51274 51235 51237 51231 51241 51237 51250 51240 51250 51243 51249 51236
51223 51232 51247 51249 51233 51237 51236 51242 51237 51248 51237 51246 51243 51235 51237
51236 51246 51223 51249 51237 51234 51233 51239 51237 51248 51236 51245 51243 51241 51237
51234 51230 51230 51271 51236 51237 51233 51237 51237 51251 51238 51243 51243 51235 51233
51223 51265 51232 51249 51235 51233 51233 51235 51236 51246 51238 51243 51244 51244 51250
51229 51274 51247 51266 51237 51237 51233 51237 51238 51241 51240 51243 51242 51235 51245
51232 51265 51231 51254 51236 51237 51233 51239 51238 51246 51242 51243 51243 51249 51237
51225 51231 51247 51248 51232 51233 51234 51239 51243 51246 51240 51243 51242 51249 51245
51237 51231 51272 51274 51235 51233 51238 51236 51237 51245 51244 51245 51243 51236 51249
51234 51235 51231 51275 51235 51236 51233 51239 51244 51248 51242 51243 51244 51250 51243
51226 51270 51269 51247 51236 51236 51234 51236 51250 51247 51241 51246 51244 51249 51243
51230 51232 51269 51246 51235 51234 51236 51237 51237 51245 51239 51243 51243 51237 51237
51232 51232 51230 51252 51236 51237 51238 51239 51237 51246 51240 51245 51241 51248 51246

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 51240 bytes 100%
1,000 51235 bytes -5 bytes 100%
10,000 51228 bytes -7 bytes 100%
100,000 51223 bytes -5 bytes 2.03%
1,000,000 51223 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
51371 bytes +148 bytes (+0.29%) +54 bytes
51317 bytes +94 bytes (+0.18%)
51351 bytes +128 bytes (+0.25%) +34 bytes
51379 bytes +156 bytes (+0.30%) +62 bytes
51373 bytes +150 bytes (+0.29%) +56 bytes
51432 bytes +209 bytes (+0.41%) +115 bytes
51432 bytes +209 bytes (+0.41%) +115 bytes
51452 bytes +229 bytes (+0.45%) +135 bytes
51466 bytes +243 bytes (+0.47%) +149 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 37737 bytes -13486 bytes (-26.33%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 44979 bytes -6244 bytes (-12.19%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 45848 bytes -5375 bytes (-10.49%)
Brotli (Wikipedia) brotli brotli -q 11 47184 bytes -4039 bytes (-7.89%)
LZMA2 (Wikipedia) xz xz -9 48244 bytes -2979 bytes (-5.82%)
ZSTD (Wikipedia) zstd zstd -19 49781 bytes -1442 bytes (-2.82%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 49968 bytes -1255 bytes (-2.45%)

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