Choose a version:
24% The original file has 375137 bytes (366.3k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 89523 bytes (87.4k, 24%).

After GZIP compression these minified files vary in size:
Boot
  35081 bytes (34.3k)
CDN
cdnjs
  30585 bytes (29.9k)
CDN
gzip -6 (default)
  30477 bytes (29.8k)
local copy
gzip -9
  30439 bytes (29.7k)
local copy
libdeflate -12
  29109 bytes (28.4k)
local copy
7zip -mx=9 -tgzip
  29068 bytes (28.4k)
local copy
kzip -s0 -rn -b0
  29044 bytes (28.4k)
local copy
zultra
  29019 bytes (28.3k)
local copy
pigz -11 -n
  28995 bytes (28.3k)
local copy
Zopfli
  28929 bytes (28.3k)
local copy
Zopfli (defluff)
  28928 bytes (28.3k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/dojo/dojo-1.4.5.min.js (or via HTTPS)

You will automatically get the smallest Dojo 1.4.5 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 1656 bytes by using my Dojo 1.4.5 Zopfli version instead of the best available CDN (5.72% smaller than cdnjs, 28929 vs. 30585 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 --i1000000 --mb8 --mls8 --bsr30 --lazy --ohh

(found February 28, 2020)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8  --mls8
block splitting recursion 30  --bsr30
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 (28928 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://download.dojotoolkit.org/release-1.4.5/dojo.js --location | md5sum
5f19a240b8a8d8519f9379330990fe97  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.4.5.min.zopfli.js.gz | md5sum
5f19a240b8a8d8519f9379330990fe97  -

SHA1:
curl --silent --compressed https://download.dojotoolkit.org/release-1.4.5/dojo.js --location | sha1sum
87d3596bbe3b1d2400639dca11b3f09769a7060e  -
curl --silent --compressed https://minime.stephan-brumme.com/files/dojo/dojo-1.4.5.min.zopfli.js.gz | sha1sum
87d3596bbe3b1d2400639dca11b3f09769a7060e  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 35081 bytes 5f19a240b8a8d8519f9379330990fe97 March 19, 2015 @ 15:31
cdnjs 30585 bytes 5f19a240b8a8d8519f9379330990fe97 February 8, 2015 @ 14:45

Note: only the MD5 hashes are shown to keep things simple.

Other Versions

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

1.17.3, 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
28929 bytes -1 byte zopfli --i1000000 --mls8 --bsr30 --lazy --ohh February 28, 2020 @ 19:32
28930 bytes -3 bytes zopfli --i100000 --mls8 --bsr30 --lazy --ohh December 1, 2015 @ 16:53
28933 bytes -6 bytes zopfli --i10000 --mls8 --bsr30 --lazy --ohh September 24, 2015 @ 17:32
28939 bytes -2 bytes zopfli --i1000 --mls8 --bsr30 --lazy --ohh September 24, 2015 @ 17:07
28941 bytes -3 bytes zopfli --i1000 --mls1024 --bsr15 --lazy --ohh September 20, 2015 @ 14:53
28944 bytes -5 bytes zopfli --i1000 --mls64 --bsr12 --lazy --ohh September 14, 2015 @ 19:30
28949 bytes zopfli --i100 --mls64 --bsr12 --lazy --ohh September 11, 2015 @ 16:35

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

Most recent activity on July 20, 2020 @ 12:53.

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
28988 28998 28994 29000 28991 28996 29000 29008 29007 28976 29002 28999 29015 29004 29004
28987 28972 28996 28995 28994 28973 28958 28983 28984 28973 28970 29007 29002 28999 28998
28975 28976 28969 28955 28963 28963 28966 28972 28984 28979 28983 29010 28988 29004 29004
28968 28978 28974 28985 28971 28978 28972 28975 28974 28975 28968 29009 28972 29008 29005
28976 28972 28973 28965 28962 28971 28965 28962 28969 28969 28960 29000 29002 29005 29002
28992 28972 28961 28976 28965 28947 28964 28964 28990 28973 28967 29000 29001 28999 28999
28976 28965 28977 28980 28964 28967 28962 28960 28974 28980 28982 29000 28978 29000 28997
28968 28971 28971 28967 28971 28965 28994 28961 28970 28988 28973 29002 28988 28997 29000
28961 28969 28969 28965 28960 28936 28962 28958 28968 28973 28973 29007 28976 28999 29004
28964 28959 28941 28959 28962 28967 28965 28958 28968 28967 28981 28951 29010 28999 28996
28969 28967 28967 28947 28965 28961 28964 28979 28976 29007 28962 29001 28992 29006 29003
28962 28974 28963 28965 28957 28988 28962 28964 28970 28934 28974 29002 29009 29004 29004
28968 28961 28971 28976 28962 28960 28967 28962 28969 28976 28973 29002 28966 29005 29004
28961 28963 28958 28963 28978 28965 28964 28967 28979 28978 28961 29000 29001 29004 29004
28974 28968 28948 28969 28965 28975 28965 28968 28974 28981 28973 29002 29008 29006 29004
28972 28981 28963 28975 28964 28968 28976 28966 28969 28980 28981 29000 28963 28997 28999
28935 28948 28947 28956 28979 28963 28967 28970 28969 28995 28984 29001 28975 28996 28995
28971 28968 28977 28966 28957 28959 28948 28968 28991 28973 28973 29000 28972 28999 29004
28947 28954 28966 28963 28964 28966 28975 28963 28974 28983 28965 29007 29011 29006 28999
28968 28970 28966 28958 28965 28969 28962 28959 28960 28976 28976 29007 28973 28996 29002
28975 28955 28971 28966 28962 28961 28971 28964 28976 28966 28956 28999 28981 29004 29004
28949 28968 28929 28958 28962 28984 28966 28965 28969 28975 28965 29001 28975 28996 28999
28963 28966 28970 28967 28950 28961 28966 28966 28975 28966 28972 29000 29013 28997 28999

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 28945 bytes 100%
1,000 28939 bytes -6 bytes 100%
10,000 28933 bytes -6 bytes 100%
100,000 28930 bytes -3 bytes 1.45%
1,000,000 28929 bytes -1 byte 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
29044 bytes +115 bytes (+0.40%)
29047 bytes +118 bytes (+0.41%) +3 bytes
29095 bytes +166 bytes (+0.57%) +51 bytes
29064 bytes +135 bytes (+0.47%) +20 bytes
29086 bytes +157 bytes (+0.54%) +42 bytes
29078 bytes +149 bytes (+0.52%) +34 bytes
29069 bytes +140 bytes (+0.48%) +25 bytes
29076 bytes +147 bytes (+0.51%) +32 bytes
29122 bytes +193 bytes (+0.67%) +78 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 23017 bytes -5912 bytes (-20.44%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 25789 bytes -3140 bytes (-10.85%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 26691 bytes -2238 bytes (-7.74%)
Brotli (Wikipedia) brotli brotli -q 11 26906 bytes -2023 bytes (-6.99%)
LZMA2 (Wikipedia) xz xz -9 27740 bytes -1189 bytes (-4.11%)
Zstandard (Wikipedia) zstd zstd -19 28493 bytes -436 bytes (-1.51%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 28621 bytes -308 bytes (-1.06%)

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 2024.
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.