Currently best Zopfli settings

Save 4024 bytes by using my Ember 2.1.0 Zopfli version instead of the best available CDN (3.73% smaller than fastcdn, 107757 vs. 111781 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 --mls512 --bsr7 --lazy --ohh

(found October 20, 2015)

Description	Value	Parameter
iterations	1000000	--i1000000
maximum blocks	8	--mb8
maximum length score	512	--mls512
block splitting recursion	7	--bsr7
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 (107754 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://builds.emberjs.com/tags/v2.1.0/ember.min.js --location | md5sum
971de40a9ff8f627645ffc2236a68ddc  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-2.1.0.min.zopfli.js.gz | md5sum
971de40a9ff8f627645ffc2236a68ddc  -

SHA1:
curl --silent --compressed https://builds.emberjs.com/tags/v2.1.0/ember.min.js --location | sha1sum
01762a4da2d9e295e1534d7b6d6b6b4b5614544b  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-2.1.0.min.zopfli.js.gz | sha1sum
01762a4da2d9e295e1534d7b6d6b6b4b5614544b  -

These CDNs send you the original file:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	138449 bytes	971de40a9ff8f627645ffc2236a68ddc	October 9, 2015 @ 23:15
cdnjs	113960 bytes	971de40a9ff8f627645ffc2236a68ddc	October 6, 2015 @ 03:20
fastcdn	111781 bytes	971de40a9ff8f627645ffc2236a68ddc	November 6, 2015 @ 06:02

And some CDNs send you a different file:

CDN	Size (compressed)	MD5 (uncompressed)	Comment / Diff	Timestamp
jsdelivr	118044 bytes	d0caa0082d4142672552772ced35901b	< e.classList?1===t.length?e.classList.add(t[0]):2===t.lengt [...] < var h=a,m=!1,d=void 0,f=h.match(/^(@?)<(.*)>$/);f&&(h=f[2] [...] < renderedNodes:this.renderedNodes,hasParentOutlet:this.hasP [...] < u.removeDependentKeys(this,e,t,l.meta(e))},h.prototype.set [...] < t},i.prototype._getInherited=function(e){for(var t=this;vo [...] < var a=i||t.meta(e),o=a.writableWatching();o[r]?o[r]=(o[r]| [...] < m=E(f.defaultValue)),v._qpDelegate=i.get(p,"_qp.states.ina [...] < t;var o=r.get(this,"content");return n.set(o,e,t)}})}),e(" [...] < return e?e:(l(),this[g])},nameClasses:function(){o([this.t [...] < e.ownerView=this.ownerView},unlinkChild:function(e){i.set( [...] [...]	(invalid)

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
107757 bytes	-2 bytes	zopfli --i1000000 --mls512 --bsr7 --lazy --ohh	October 20, 2015 @ 10:27
107759 bytes	-2 bytes	zopfli --i100000 --mls512 --bsr7 --lazy --ohh	October 10, 2015 @ 06:32
107761 bytes	-1 byte	zopfli --i100000 --mls128 --bsr7 --lazy --ohh	October 9, 2015 @ 23:07
107762 bytes	-4 bytes	zopfli --i100000 --mls64 --bsr25 --lazy --ohh	October 5, 2015 @ 18:44
107766 bytes	-4 bytes	zopfli --i10000 --mls64 --bsr25 --lazy --ohh	October 5, 2015 @ 13:23
107770 bytes	-1 byte	zopfli --i1000 --mls64 --bsr25 --lazy --ohh	October 5, 2015 @ 10:47
107771 bytes	-3 bytes	zopfli --i1000 --mls64 --bsr17 --lazy --ohh	October 5, 2015 @ 10:45
107774 bytes	-46 bytes	zopfli --i1000 --mls2048 --bsr30 --lazy --ohh	October 5, 2015 @ 10:29
107820 bytes	–	zopfli --i100 --mls2048 --bsr30 --lazy --ohh	October 5, 2015 @ 09:58

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 @ 12:54.

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
2	107940	107920	107942	107920	107940	107883	107943	107942	107928	107919	107924	107921	107929	107942	107945
4	107823	107823	107899	107899	107895	107903	107896	107791	107779	107792	107800	107799	107824	107804	107902
6	107780	107775	107789	107780	107784	107784	107787	107786	107786	107792	107816	107815	107792	107942	107945
7	107780	107775	107895	107899	107901	107778	107759	107769	107757	107900	107899	107788	107781	107900	107900
8	107773	107772	107899	107898	107898	107774	107901	107900	107901	107898	107898	107794	107901	107901	107900
9	107783	107806	107895	107898	107896	107808	107900	107896	107896	107898	107981	107797	107904	107901	107896
10	107775	107776	107895	107899	107898	107801	107901	107898	107898	107897	107900	107896	107779	107900	107901
11	107774	107774	107899	107895	107900	107782	107901	107897	107896	107898	107816	107797	107785	107900	107894
12	107773	107772	107894	107899	107900	107789	107900	107897	107902	107898	107901	107796	107898	107900	107898
13	107774	107774	107899	107899	107896	107792	107899	107901	107897	107898	107771	107793	107782	107900	107900
14	107775	107773	107895	107896	107900	107764	107895	107896	107897	107900	107820	107791	107899	107900	107901
15	107775	107775	107895	107899	107900	107797	107901	107898	107898	107901	107902	107785	107898	107901	107900
16	107772	107760	107899	107900	107896	107809	107905	107903	107899	107900	107900	107791	107811	107900	107901
17	107777	107767	107897	107896	107899	107761	107895	107897	107902	107898	107981	107789	107787	107900	107900
18	107772	107773	107895	107896	107896	107770	107901	107896	107896	107898	107899	107803	107901	107903	107901
19	107775	107775	107899	107899	107896	107796	107895	107896	107898	107901	107795	107810	107789	107901	107898
20	107777	107774	107895	107901	107896	107793	107899	107902	107898	107898	107981	107793	107781	107901	107896
21	107778	107770	107899	107899	107896	107792	107897	107898	107898	107899	107899	107799	107901	107901	107896
22	107771	107771	107895	107899	107897	107768	107896	107896	107898	107895	107901	107798	107787	107902	107896
23	107780	107774	107895	107899	107899	107772	107899	107901	107899	107894	107981	107796	107906	107899	107901
25	107773	107773	107895	107895	107900	107762	107898	107896	107898	107900	107981	107806	107903	107899	107895
30	107775	107775	107895	107896	107896	107769	107895	107896	107900	107899	107762	107792	107898	107900	107898
40	107771	107773	107900	107899	107898	107797	107900	107896	107902	107899	107981	107790	107898	107904	107900

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	107820 bytes	–	100%
1,000	107770 bytes	-50 bytes	100%
10,000	107766 bytes	-4 bytes	100%
100,000	107759 bytes	-7 bytes	2.03%
1,000,000	107757 bytes	-2 bytes	0.87%
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)	107786 bytes	+29 bytes (+0.03%)	–
1	107936 bytes	+179 bytes (+0.17%)	+150 bytes
2	107922 bytes	+165 bytes (+0.15%)	+136 bytes
3	107876 bytes	+119 bytes (+0.11%)	+90 bytes
4	107818 bytes	+61 bytes (+0.06%)	+32 bytes
5	107791 bytes	+34 bytes (+0.03%)	+5 bytes
6	107825 bytes	+68 bytes (+0.06%)	+39 bytes
7	107867 bytes	+110 bytes (+0.10%)	+81 bytes
8	107914 bytes	+157 bytes (+0.15%)	+128 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	73835 bytes	-33922 bytes (-31.48%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	79060 bytes	-28697 bytes (-26.63%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	84977 bytes	-22780 bytes (-21.14%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	89887 bytes	-17870 bytes (-16.58%)
Brotli (Wikipedia)	brotli	brotli -q 11	93899 bytes	-13858 bytes (-12.86%)
LZMA2 (Wikipedia)	xz	xz -9	96044 bytes	-11713 bytes (-10.87%)
Zstandard (Wikipedia)	zstd	zstd -19	98726 bytes	-9031 bytes (-8.38%)

Detailled Analysis