Currently best Zopfli settings

Save 4849 bytes by using my Ember 1.13.0 Zopfli version instead of the best available CDN (3.76% smaller than jsdelivr, 129013 vs. 133862 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 --mls4 --bsr6 --lazy --ohh

(found March 27, 2017)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	4	--mls4
block splitting recursion	6	--bsr6
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 6 more bytes (129007 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://builds.emberjs.com/tags/v1.13.0/ember.min.js --location | md5sum
8d242db9d91144c9db30972c68df0638  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-1.13.0.min.zopfli.js.gz | md5sum
8d242db9d91144c9db30972c68df0638  -

SHA1:
curl --silent --compressed https://builds.emberjs.com/tags/v1.13.0/ember.min.js --location | sha1sum
22e99c135b4671979b59eb9b72342db25ca7cb90  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-1.13.0.min.zopfli.js.gz | sha1sum
22e99c135b4671979b59eb9b72342db25ca7cb90  -

These CDNs send you the original file:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	165201 bytes	8d242db9d91144c9db30972c68df0638	June 13, 2015 @ 22:17
cdnjs	136121 bytes	8d242db9d91144c9db30972c68df0638	June 13, 2015 @ 12:30
jsdelivr	133862 bytes	8d242db9d91144c9db30972c68df0638	June 13, 2015 @ 10:13

And some CDNs send you a different file:

CDN	Size (compressed)	MD5 (uncompressed)	Comment / Diff	Timestamp
Baidu	136270 bytes	ed127dabc56fbc220924e6aed3e3488e	< var G=n["default"]({},r.hooks);G.keywords=O["default"],n[" [...] < var o=this.expectElement&&this.renderNode.firstNode;x(r,o) [...] < }),e.SafeString=t.SafeString,e.htmlSafe=n,e.escapeExpressi [...] > var G=n["default"]({},r.hooks);G.keywords=O["default"],n[" [...] > var i=e.childWithView(r),a=k(n);i.renderer.componentInitAt [...] > return null===e||void 0===e?"":("string"!=typeof e&&(e=""+ [...] < 1===c.length)t["default"].assert('You can only use the {{r [...] > 1===c.length)t["default"].assert('You can only use the {{r [...] < },toString:function(){var e="";return r.forEach(this._oper [...] < this.elementId=null),s&&(this.dom.setAttribute(p,"class",s [...] [...]	July 3, 2015 @ 08:31

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

Other Versions

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

3.0.0,
2.18.2, 2.18.1, 2.18.0,
2.17.2, 2.17.1, 2.17.0,
2.16.2, 2.16.1, 2.16.0,
2.15.3, 2.15.2, 2.15.1, 2.15.0,
2.14.1, 2.14.0,
2.13.4, 2.13.3, 2.13.2, 2.13.1, 2.13.0,
2.12.2, 2.12.1, 2.12.0,
2.11.3, 2.11.2, 2.11.1, 2.11.0,
2.10.2, 2.10.1, 2.10.0,
2.9.1, 2.9.0,
2.8.3, 2.8.2, 2.8.1, 2.8.0,
2.7.3, 2.7.2, 2.7.1, 2.7.0,
2.6.2, 2.6.1, 2.6.0,
2.5.1, 2.5.0,
2.4.6, 2.4.5, 2.4.4, 2.4.3, 2.4.2, 2.4.1, 2.4.0,
2.3.1, 2.3.0,
2.2.2, 2.2.1, 2.2.0,
2.1.2, 2.1.1, 2.1.0,
2.0.3, 2.0.2, 2.0.1, 2.0.0,
1.13.13, 1.13.12, 1.13.11, 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,
1.12.2, 1.12.1, 1.12.0,
1.11.4, 1.11.3, 1.11.2, 1.11.1, 1.11.0,
1.10.1, 1.10.0,
1.9.1, 1.9.0,
1.8.1, 1.8.0,
1.7.1, 1.7.0,
1.6.1, 1.6.0,
1.5.1, 1.5.0,
1.4.0,
1.3.2, 1.3.1, 1.3.0,
1.2.2, 1.2.1, 1.2.0,
1.0.1, 1.0.0

The project site contains an overview how well these versions were compressed.
Other interesting projects are AngularJS, BackboneJS, Bootstrap, D3, Dojo, jQuery, Knockout, lodash, React, Socket.IO, ThreeJS, UnderscoreJS and Vue.

Changelog

Best Zopfli parameters so far:

Size	Improvement	Parameters	Found
129013 bytes	-10 bytes	zopfli --i100000 --mls4 --bsr6 --lazy --ohh	March 27, 2017 @ 01:16
129023 bytes	-3 bytes	zopfli --i100000 --mls128 --bsr40 --lazy --ohh	July 21, 2016 @ 22:55
129026 bytes	-10 bytes	zopfli --i100000 --mls1024 --bsr18 --lazy --ohh	July 21, 2016 @ 20:31
129036 bytes	-1 byte	zopfli --i10000 --mls1024 --bsr18 --lazy --ohh	November 22, 2015 @ 13:26
129037 bytes	-8 bytes	zopfli --i10000 --mls64 --bsr9 --lazy --ohh	October 6, 2015 @ 15:23
129045 bytes	-1 byte	zopfli --i1000 --mls1024 --bsr18 --lazy --ohh	October 6, 2015 @ 13:43
129046 bytes	-1 byte	zopfli --i1000 --mls2 --bsr22 --lazy --ohh	October 6, 2015 @ 13:22
129047 bytes	-8 bytes	zopfli --i1000 --mls16 --bsr16 --lazy --ohh	October 6, 2015 @ 11:44
129055 bytes	-1 byte	zopfli --i1000 --mls16 --bsr30 --lazy --ohh	October 6, 2015 @ 11:43
129056 bytes	-25 bytes	zopfli --i1000 --mls16 --bsr9 --lazy --ohh	October 6, 2015 @ 11:35
129081 bytes	–	zopfli --i100 --mls256 --bsr22 --lazy --ohh	October 5, 2015 @ 11:49

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 @ 12:47.

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
2	129118	129121	129109	129110	129118	129116	129114	129046	129103	129095	129120	129116	129111	129095	129123
4	129051	129042	129034	129035	129043	129052	129044	129044	129049	129037	129044	129058	129052	129095	129053
6	129057	129013	129051	129057	129053	129116	129114	129038	129103	129095	129047	129049	129049	129095	129123
7	129047	129038	129033	129042	129037	129036	129041	129045	129045	129047	129056	129149	129060	129064	129065
8	129043	129042	129053	129033	129037	129037	129036	129046	129048	129046	129042	129048	129049	129049	129054
9	129043	129053	129043	129042	129037	129037	129041	129038	129045	129039	129053	129037	129048	129050	129065
10	129043	129043	129048	129042	129037	129037	129036	129045	129050	129037	129038	129044	129048	129052	129047
11	129047	129044	129033	129033	129049	129047	129043	129046	129045	129037	129037	129150	129052	129050	129057
12	129042	129042	129047	129054	129048	129037	129037	129045	129048	129037	129038	129150	129064	129063	129055
13	129043	129050	129044	129034	129037	129042	129036	129038	129048	129037	129047	129043	129042	129064	129065
14	129043	129038	129043	129042	129037	129037	129037	129037	129045	129037	129047	129044	129058	129049	129047
15	129046	129050	129033	129026	129037	129037	129037	129045	129045	129037	129037	129044	129045	129052	129055
16	129044	129044	129048	129037	129046	129043	129049	129045	129045	129042	129038	129047	129054	129063	129054
17	129046	129042	129045	129046	129042	129037	129047	129048	129050	129043	129042	129045	129053	129062	129065
18	129021	129043	129042	129043	129041	129047	129037	129051	129045	129026	129038	129046	129053	129063	129053
19	129043	129044	129043	129039	129037	129041	129026	129039	129046	129042	129047	129044	129051	129050	129065
20	129071	129050	129043	129034	129037	129037	129037	129044	129045	129037	129047	129044	129044	129062	129049
21	129038	129043	129043	129054	129042	129035	129036	129044	129050	129046	129047	129044	129052	129064	129065
22	129039	129038	129033	129054	129037	129037	129036	129046	129050	129037	129040	129150	129052	129065	129031
23	129043	129044	129033	129043	129037	129042	129042	129042	129045	129037	129044	129044	129045	129060	129046
25	129043	129043	129033	129034	129037	129037	129036	129045	129048	129039	129052	129044	129052	129052	129055
30	129038	129040	129083	129034	129037	129037	129043	129039	129045	129038	129037	129044	129053	129062	129049
40	129053	129043	129034	129033	129049	129037	129023	129154	129046	129037	129047	129052	129042	129063	129065

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	129081 bytes	–	100%
1,000	129045 bytes	-36 bytes	100%
10,000	129025 bytes	-20 bytes	100%
100,000	129013 bytes	-12 bytes	1.16%
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
(any)	129092 bytes	+79 bytes (+0.06%)	+30 bytes
1	129062 bytes	+49 bytes (+0.04%)	–
2	129101 bytes	+88 bytes (+0.07%)	+39 bytes
3	129172 bytes	+159 bytes (+0.12%)	+110 bytes
4	129187 bytes	+174 bytes (+0.13%)	+125 bytes
5	129153 bytes	+140 bytes (+0.11%)	+91 bytes
6	129129 bytes	+116 bytes (+0.09%)	+67 bytes
7	129168 bytes	+155 bytes (+0.12%)	+106 bytes
8	129155 bytes	+142 bytes (+0.11%)	+93 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	87574 bytes	-41439 bytes (-32.12%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	93603 bytes	-35410 bytes (-27.45%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	102275 bytes	-26738 bytes (-20.73%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	106639 bytes	-22374 bytes (-17.34%)
Brotli (Wikipedia)	brotli	brotli -q 11	111441 bytes	-17572 bytes (-13.62%)
LZMA2 (Wikipedia)	xz	xz -9	113928 bytes	-15085 bytes (-11.69%)
Zstandard (Wikipedia)	zstd	zstd -19	116958 bytes	-12055 bytes (-9.34%)

Detailled Analysis