Choose a version:
27% The original file has 1724549 bytes (1,684.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 460998 bytes (450.2k, 27%).

After GZIP compression these minified files vary in size:
Boot
  145235 bytes (141.8k)
CDN
cdnjs
  119096 bytes (116.3k)
CDN
gzip -6 (default)
  117264 bytes (114.5k)
local copy
gzip -9
  116859 bytes (114.1k)
local copy
cdnhttps
  116742 bytes (114.0k)
CDN
jsdelivr
  116705 bytes (114.0k)
CDN
7zip -mx=9 -tgzip
  113041 bytes (110.4k)
local copy
libdeflate -12
  112895 bytes (110.2k)
local copy
pigz -11 -n
  112808 bytes (110.2k)
local copy
kzip -s0 -rn -b5
  112677 bytes (110.0k)
local copy
Zopfli
  112593 bytes (110.0k)
local copy
Zopfli (defluff)
  112592 bytes (110.0k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-2.5.0.min.js (or via HTTPS)

You will automatically get the smallest Ember 2.5.0 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 4112 bytes by using my Ember 2.5.0 Zopfli version instead of the best available CDN (3.65% smaller than jsdelivr, 112593 vs. 116705 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 --mls64 --bsr18 --lazy --ohh

(found April 15, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 64  --mls64
block splitting recursion 18  --bsr18
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 (112592 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://builds.emberjs.com/tags/v2.5.0/ember.min.js --location | md5sum
4a745f028a0220428db483abadebcbf5  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-2.5.0.min.zopfli.js.gz | md5sum
4a745f028a0220428db483abadebcbf5  -

SHA1:
curl --silent --compressed https://builds.emberjs.com/tags/v2.5.0/ember.min.js --location | sha1sum
49d6139df5336fb96cc62631fac0704cb400baae  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-2.5.0.min.zopfli.js.gz | sha1sum
49d6139df5336fb96cc62631fac0704cb400baae  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 145235 bytes 4a745f028a0220428db483abadebcbf5 May 3, 2016 @ 11:52
cdnjs 119096 bytes 4a745f028a0220428db483abadebcbf5 April 12, 2016 @ 01:01
cdnhttps 116742 bytes 4a745f028a0220428db483abadebcbf5 November 22, 2016 @ 16:33

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
jsdelivr 116705 bytes 81e1ca85c584ff8b626697c60b0f1e87 < }):void(a.inverse["yield"]&&a.inverse["yield"]())}function [...]
> }):void(a.inverse["yield"]&&a.inverse["yield"]())}function [...]
< locals:["item"],templates:[]}}();return{meta:{},isEmpty:!1 [...]
< return o});return s?n(r,s,o,a):r.call(a)}function n(e,t,r, [...]
< "use strict";function h(e){this._init(e)}function d(e,t,r) [...]
< if(n?(n=n.replace(/\//g,"."),s=n):(n=e.routeName,s=e.templ [...]
< var A={layout:null,self:k};_&&(A.component=_);var S=u["def [...]
< return 0===e?this:(this.replace(0,e,u),this)},insertAt:fun [...]
< s(t.hash.pairs,function(t){var n=t.value;"SubExpression"== [...]
< function o(e){if(a.isStream(e))return new s(e);var t=typeo [...]
[...]
(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
112593 bytes -1 byte zopfli --i1000000 --mls64 --bsr18 --lazy --ohh April 15, 2016 @ 09:15
112594 bytes -2 bytes zopfli --i100000 --mls64 --bsr18 --lazy --ohh April 12, 2016 @ 22:37
112596 bytes -13 bytes zopfli --i100000 --mls64 --bsr25 --lazy --ohh April 12, 2016 @ 16:40
112609 bytes -3 bytes zopfli --i10000 --mls64 --bsr15 --lazy --ohh April 12, 2016 @ 12:19
112612 bytes -6 bytes zopfli --i10000 --mls2048 --bsr6 --lazy --ohh April 12, 2016 @ 11:42
112618 bytes -1 byte zopfli --i1000 --mls32 --bsr10 --lazy --ohh April 12, 2016 @ 11:29
112619 bytes -27 bytes zopfli --i1000 --mls2048 --bsr6 --lazy --ohh April 12, 2016 @ 11:23
112646 bytes zopfli --i100 --mls2048 --bsr6 --lazy --ohh April 12, 2016 @ 10:45

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

Most recent activity on November 22, 2016 @ 16:33.

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
112714 112710 112736 112732 112716 112720 112718 112725 112728 112725 112726 112723 112779 112730 112783
112634 112633 112725 112632 112612 112609 112726 112625 112628 112638 112669 112728 112779 112635 112734
112609 112608 112615 112611 112623 112632 112636 112642 112617 112642 112612 112621 112779 112640 112783
112720 112731 112724 112722 112612 112717 112720 112724 112720 112722 112719 112725 112723 112622 112722
112724 112723 112727 112727 112606 112717 112727 112797 112720 112724 112724 112716 112729 112635 112724
112726 112729 112720 112717 112617 112730 112723 112728 112717 112725 112724 112719 112723 112723 112723
112720 112724 112725 112727 112612 112717 112723 112726 112717 112722 112723 112721 112625 112722 112724
112722 112720 112717 112727 112611 112717 112723 112728 112717 112722 112729 112716 112722 112718 112723
112724 112724 112717 112724 112723 112717 112723 112728 112723 112722 112724 112721 112624 112723 112734
112723 112721 112720 112717 112610 112717 112717 112726 112724 112723 112725 112716 112725 112719 112724
112719 112724 112725 112721 112623 112609 112726 112728 112723 112722 112727 112721 112621 112723 112724
112720 112724 112717 112722 112615 112596 112723 112728 112723 112725 112728 112723 112722 112722 112724
112727 112725 112723 112726 112609 112724 112723 112724 112723 112725 112719 112721 112625 112718 112724
112722 112721 112724 112717 112610 112724 112724 112728 112717 112725 112724 112717 112722 112723 112722
112725 112722 112725 112720 112612 112593 112726 112724 112723 112722 112719 112730 112624 112721 112723
112722 112725 112725 112717 112724 112716 112723 112718 112723 112728 112730 112722 112723 112723 112724
112722 112721 112717 112717 112614 112615 112723 112726 112723 112724 112730 112716 112622 112723 112724
112723 112724 112717 112727 112610 112717 112723 112728 112721 112722 112737 112723 112630 112718 112723
112720 112724 112725 112727 112611 112612 112723 112728 112720 112722 112724 112717 112627 112719 112722
112720 112724 112728 112717 112611 112724 112717 112728 112724 112722 112719 112725 112725 112724 112722
112720 112724 112717 112727 112610 112596 112717 112721 112723 112722 112728 112723 112724 112723 112723
112722 112720 112725 112725 112595 112724 112723 112724 112723 112725 112724 112723 112626 112718 112724
112722 112724 112725 112717 112618 112717 112723 112724 112723 112725 112728 112719 112722 112725 112724

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 112646 bytes 100%
1,000 112617 bytes -29 bytes 100%
10,000 112603 bytes -14 bytes 100%
100,000 112594 bytes -9 bytes 1.16%
1,000,000 112593 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
112790 bytes +197 bytes (+0.17%) +113 bytes
112736 bytes +143 bytes (+0.13%) +59 bytes
112789 bytes +196 bytes (+0.17%) +112 bytes
112748 bytes +155 bytes (+0.14%) +71 bytes
112769 bytes +176 bytes (+0.16%) +92 bytes
112677 bytes +84 bytes (+0.07%)
112736 bytes +143 bytes (+0.13%) +59 bytes
112770 bytes +177 bytes (+0.16%) +93 bytes
112806 bytes +213 bytes (+0.19%) +129 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 76654 bytes -35939 bytes (-31.92%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 82127 bytes -30466 bytes (-27.06%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 88612 bytes -23981 bytes (-21.30%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 93430 bytes -19163 bytes (-17.02%)
Brotli (Wikipedia) brotli brotli -q 11 97721 bytes -14872 bytes (-13.21%)
LZMA2 (Wikipedia) xz xz -9 99868 bytes -12725 bytes (-11.30%)
Zstandard (Wikipedia) zstd zstd -19 102683 bytes -9910 bytes (-8.80%)

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