Choose a version:
26% The original file has 611897 bytes (597.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 159739 bytes (156.0k, 26%).

After GZIP compression these minified files vary in size:
gzip -6 (default)
  54085 bytes (52.8k)
local copy
gzip -9
  54034 bytes (52.8k)
local copy
7zip -mx=9 -tgzip
  51446 bytes (50.2k)
local copy
libdeflate -12
  51393 bytes (50.2k)
local copy
kzip -s0 -rn -b1
  51358 bytes (50.2k)
local copy
pigz -11 -n
  51355 bytes (50.2k)
local copy
Zopfli
  51265 bytes (50.1k)
local copy
Zopfli (defluff)
  51262 bytes (50.1k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.8.14.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.8.14 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 --mls8 --bsr16 --lazy --ohh

(found July 6, 2018)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 8  --mls8
block splitting recursion 16  --bsr16
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 3 more bytes (51262 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://download.dojotoolkit.org/release-1.8.14/dojo.js --location | md5sum
bac1bfa81d9489d09c10cc1852a4aae4  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.8.14.min.zopfli.js.gz | md5sum
bac1bfa81d9489d09c10cc1852a4aae4  -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.8.14/dojo.js --location | sha1sum
57a64edc1c51d6652a5e9e27dcb38ceeeb98ad4b  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.8.14.min.zopfli.js.gz | sha1sum
57a64edc1c51d6652a5e9e27dcb38ceeeb98ad4b  -

Other Versions

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

1.14.0,
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,
1.8.14, 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,
1.7.10, 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
51265 bytes -5 bytes zopfli --i100000 --mls8 --bsr16 --lazy --ohh July 6, 2018 @ 08:59
51270 bytes -1 byte zopfli --i10000 --mls8 --bsr16 --lazy --ohh July 5, 2018 @ 20:41
51271 bytes -1 byte zopfli --i10000 --mls2 --bsr11 --lazy --ohh July 5, 2018 @ 20:36
51272 bytes -1 byte zopfli --i10000 --mls2 --bsr20 --lazy --ohh July 5, 2018 @ 19:56
51273 bytes -3 bytes zopfli --i10000 --mls2 --bsr19 --lazy --ohh July 5, 2018 @ 19:35
51276 bytes -1 byte zopfli --i1000 --mls2 --bsr21 --lazy --ohh July 5, 2018 @ 16:25
51277 bytes -5 bytes zopfli --i1000 --mls2 --bsr30 --lazy --ohh July 5, 2018 @ 16:24
51282 bytes zopfli --i100 --mls2 --bsr12 --lazy --ohh July 5, 2018 @ 16:11

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

Most recent activity on July 6, 2018 @ 13:07.

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
51277 51287 51279 51282 51277 51285 51281 51283 51288 51284 51300 51299 51300 51304 51309
51282 51274 51288 51288 51293 51279 51277 51278 51278 51281 51280 51287 51287 51288 51282
51273 51277 51315 51299 51280 51276 51275 51279 51279 51287 51281 51286 51284 51279 51285
51276 51314 51320 51318 51280 51281 51282 51278 51279 51290 51283 51288 51282 51279 51279
51311 51273 51293 51290 51282 51279 51276 51279 51282 51282 51284 51284 51282 51283 51285
51273 51289 51325 51293 51277 51278 51277 51277 51279 51290 51293 51296 51287 51284 51280
51281 51277 51309 51281 51286 51281 51277 51281 51281 51281 51281 51288 51284 51281 51294
51265 51294 51291 51294 51280 51273 51279 51278 51287 51290 51282 51284 51282 51286 51280
51272 51278 51310 51297 51289 51276 51279 51279 51279 51290 51283 51289 51284 51292 51296
51310 51275 51319 51289 51279 51279 51276 51278 51286 51288 51322 51287 51285 51277 51298
51308 51292 51318 51291 51279 51280 51277 51283 51279 51290 51280 51284 51285 51279 51280
51273 51315 51289 51295 51276 51281 51280 51284 51279 51290 51280 51287 51282 51281 51280
51280 51288 51265 51290 51280 51281 51276 51281 51279 51288 51281 51287 51282 51283 51281
51276 51316 51272 51292 51280 51280 51280 51279 51279 51293 51282 51288 51281 51277 51278
51275 51314 51274 51291 51291 51278 51276 51278 51279 51290 51281 51290 51284 51292 51277
51273 51316 51296 51290 51293 51281 51276 51279 51282 51288 51284 51289 51286 51277 51288
51272 51275 51297 51294 51282 51280 51276 51276 51282 51288 51323 51288 51285 51291 51280
51273 51308 51291 51287 51275 51276 51277 51280 51278 51288 51281 51284 51283 51284 51286
51279 51273 51313 51315 51278 51277 51284 51279 51280 51290 51282 51288 51285 51279 51293
51274 51304 51316 51281 51278 51281 51278 51279 51285 51290 51281 51288 51285 51287 51285
51272 51320 51288 51289 51278 51280 51275 51278 51280 51289 51322 51288 51284 51294 51288
51273 51317 51314 51288 51282 51276 51278 51281 51279 51292 51282 51284 51284 51283 51284
51273 51309 51272 51292 51279 51281 51278 51281 51279 51290 51283 51284 51284 51287 51288

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 51282 bytes 100%
1,000 51276 bytes -6 bytes 100%
10,000 51270 bytes -6 bytes 100%
100,000 51265 bytes -5 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
51420 bytes +155 bytes (+0.30%) +62 bytes
51358 bytes +93 bytes (+0.18%)
51386 bytes +121 bytes (+0.24%) +28 bytes
51421 bytes +156 bytes (+0.30%) +63 bytes
51423 bytes +158 bytes (+0.31%) +65 bytes
51467 bytes +202 bytes (+0.39%) +109 bytes
51477 bytes +212 bytes (+0.41%) +119 bytes
51490 bytes +225 bytes (+0.44%) +132 bytes
51506 bytes +241 bytes (+0.47%) +148 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 37763 bytes -13502 bytes (-26.34%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 45019 bytes -6246 bytes (-12.18%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 45908 bytes -5357 bytes (-10.45%)
Brotli (Wikipedia) brotli brotli -q 11 47256 bytes -4009 bytes (-7.82%)
LZMA2 (Wikipedia) xz xz -9 48292 bytes -2973 bytes (-5.80%)
Zstandard (Wikipedia) zstd zstd -19 49713 bytes -1552 bytes (-3.03%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 49910 bytes -1355 bytes (-2.64%)

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