Choose a version:
26% The original file has 633110 bytes (618.3k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 165940 bytes (162.1k, 26%).

After GZIP compression these minified files vary in size:
gzip -6 (default)
  55931 bytes (54.6k)
local copy
gzip -9
  55874 bytes (54.6k)
local copy
libdeflate -12
  53235 bytes (52.0k)
local copy
7zip -mx=9 -tgzip
  53213 bytes (52.0k)
local copy
zultra
  53143 bytes (51.9k)
local copy
pigz -11 -n
  53141 bytes (51.9k)
local copy
kzip -s0 -rn -b1
  53135 bytes (51.9k)
local copy
Zopfli
  53041 bytes (51.8k)
local copy
Zopfli (defluff)
  53037 bytes (51.8k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.12.9.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.12.9 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 --i1000000 --mb8 --mls8 --bsr40 --lazy --ohh

(found March 10, 2022)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8  --mls8
block splitting recursion 40  --bsr40
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 4 more bytes (53037 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://download.dojotoolkit.org/release-1.12.9/dojo.js --location | md5sum
be31450eb1f3172714bd086d0858652e  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.12.9.min.zopfli.js.gz | md5sum
be31450eb1f3172714bd086d0858652e  -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.12.9/dojo.js --location | sha1sum
0404cc7a4662e8ccaf21359118fb322437a2e914  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.12.9.min.zopfli.js.gz | sha1sum
0404cc7a4662e8ccaf21359118fb322437a2e914  -

Other Versions

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

1.17.2, 1.17.1, 1.17.0,
1.16.5, 1.16.4, 1.16.3, 1.16.2, 1.16.1, 1.16.0,
1.15.6, 1.15.5, 1.15.4, 1.15.3, 1.15.2, 1.15.1, 1.15.0,
1.14.9, 1.14.8, 1.14.7, 1.14.6, 1.14.5, 1.14.4, 1.14.3, 1.14.2, 1.14.1, 1.14.0,
1.13.10, 1.13.9, 1.13.8, 1.13.7, 1.13.6, 1.13.5, 1.13.4, 1.13.3, 1.13.2, 1.13.1, 1.13.0,
1.12.11, 1.12.10, 1.12.9, 1.12.8, 1.12.7, 1.12.6, 1.12.5, 1.12.4, 1.12.3, 1.12.2, 1.12.1,
1.11.13, 1.11.12, 1.11.11, 1.11.10, 1.11.9, 1.11.8, 1.11.7, 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,
1.6.5, 1.6.4, 1.6.3, 1.6.2, 1.6.1, 1.6.0,
1.5.6, 1.5.5, 1.5.4, 1.5.3, 1.5.2, 1.5.1, 1.5.0,
1.4.8, 1.4.7, 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, 1.2.2

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
53041 bytes -1 byte zopfli --i1000000 --mls8 --bsr40 --lazy --ohh March 10, 2022 @ 07:13
53042 bytes -7 bytes zopfli --i100000 --mls8 --bsr10 --lazy --ohh March 5, 2022 @ 08:42
53049 bytes -2 bytes zopfli --i10000 --mls8 --bsr10 --lazy --ohh February 26, 2022 @ 04:02
53051 bytes -3 bytes zopfli --i10000 --mls256 --bsr7 --lazy --ohh February 25, 2022 @ 06:44
53054 bytes -1 byte zopfli --i1000 --mls8 --bsr10 --lazy --ohh February 24, 2022 @ 23:31
53055 bytes -1 byte zopfli --i1000 --mls32 --bsr25 --lazy --ohh February 24, 2022 @ 18:18
53056 bytes zopfli --i100 --mls32 --bsr25 --lazy --ohh February 24, 2022 @ 16:42

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

Most recent activity on March 10, 2022 @ 14:05.

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
53053 53053 53054 53055 53054 53053 53055 53054 53053 53054 53063 53056 53061 53082 53087
53080 53053 53052 53054 53062 53056 53054 53052 53057 53067 53062 53056 53059 53063 53076
53091 53094 53054 53053 53058 53054 53053 53053 53059 53071 53071 53061 53062 53060 53064
53088 53052 53060 53092 53053 53054 53052 53051 53058 53060 53074 53061 53056 53077 53077
53083 53082 53051 53070 53052 53069 53053 53054 53064 53065 53068 53054 53069 53062 53069
53095 53080 53053 53058 53053 53055 53052 53054 53057 53070 53063 53054 53065 53064 53064
53052 53082 53042 53090 53055 53052 53059 53053 53058 53062 53075 53055 53064 53061 53067
53085 53079 53051 53053 53057 53051 53054 53051 53054 53064 53063 53060 53063 53071 53062
53055 53052 53050 53084 53056 53069 53043 53056 53058 53062 53064 53063 53063 53068 53064
53083 53091 53053 53055 53054 53063 53052 53054 53058 53064 53060 53054 53066 53079 53071
53052 53052 53050 53056 53056 53055 53054 53054 53058 53064 53075 53060 53065 53071 53062
53085 53085 53050 53056 53053 53056 53052 53055 53064 53062 53074 53060 53061 53077 53067
53058 53051 53053 53051 53053 53056 53054 53054 53065 53065 53059 53055 53063 53075 53065
53089 53081 53054 53054 53053 53054 53053 53058 53058 53068 53063 53059 53066 53063 53064
53085 53083 53053 53055 53057 53054 53052 53058 53058 53067 53074 53061 53064 53067 53065
53088 53091 53050 53053 53053 53069 53054 53054 53060 53061 53064 53063 53058 53061 53065
53085 53095 53051 53054 53057 53053 53053 53058 53059 53063 53075 53061 53064 53072 53069
53085 53080 53054 53054 53056 53068 53055 53053 53058 53066 53069 53056 53066 53060 53071
53089 53083 53042 53054 53057 53061 53052 53053 53058 53062 53077 53060 53063 53058 53065
53086 53080 53052 53091 53051 53041 53050 53051 53067 53066 53063 53054 53064 53076 53067
53080 53079 53054 53053 53051 53054 53053 53058 53059 53064 53063 53064 53069 53072 53067
53082 53076 53055 53053 53053 53050 53054 53054 53059 53061 53060 53061 53066 53072 53067
53083 53094 53041 53053 53053 53049 53054 53054 53058 53061 53074 53059 53068 53060 53064

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 53056 bytes 100%
1,000 53054 bytes -2 bytes 100%
10,000 53049 bytes -5 bytes 100%
100,000 53042 bytes -7 bytes 1.74%
1,000,000 53041 bytes -1 byte 1.16%
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
53167 bytes +126 bytes (+0.24%) +32 bytes
53135 bytes +94 bytes (+0.18%)
53170 bytes +129 bytes (+0.24%) +35 bytes
53192 bytes +151 bytes (+0.28%) +57 bytes
53221 bytes +180 bytes (+0.34%) +86 bytes
53247 bytes +206 bytes (+0.39%) +112 bytes
53296 bytes +255 bytes (+0.48%) +161 bytes
53309 bytes +268 bytes (+0.51%) +174 bytes
53292 bytes +251 bytes (+0.47%) +157 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 - for example, your browser actually supports it !
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 38995 bytes -14046 bytes (-26.48%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 46541 bytes -6500 bytes (-12.25%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 47516 bytes -5525 bytes (-10.42%)
Brotli (Wikipedia) brotli brotli -q 11 48915 bytes -4126 bytes (-7.78%)
LZMA2 (Wikipedia) xz xz -9 50036 bytes -3005 bytes (-5.67%)
Zstandard (Wikipedia) zstd zstd -19 51359 bytes -1682 bytes (-3.17%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 51590 bytes -1451 bytes (-2.74%)

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 2022.
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

All trademarks are property of their respective owners. You know, the boring legal stuff.