Choose a version:
28% The original file has 1871367 bytes (1,827.5k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 532243 bytes (519.8k, 28%).

After GZIP compression these minified files vary in size:
Boot
  164358 bytes (160.5k)
CDN, direct link
cdnjs
  134051 bytes (130.9k)
CDN, direct link
gzip -6 (default)
  132223 bytes (129.1k)
local copy
gzip -9
  131692 bytes (128.6k)
local copy
7zip -mx=9 -tgzip
  127116 bytes (124.1k)
local copy
libdeflate -12
  126927 bytes (124.0k)
local copy
pigz -11 -n
  126902 bytes (123.9k)
local copy
kzip -s0 -rn -b5
  126706 bytes (123.7k)
local copy
Zopfli
  126641 bytes (123.7k)
local copy
Zopfli (defluff)
  126639 bytes (123.7k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-2.12.2.min.js

You will automatically get the smallest Ember 2.12.2 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 7410 bytes by using my Ember 2.12.2 Zopfli version instead of the best available CDN (5.85% smaller than cdnjs, 126641 vs. 134051 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 --mls16384 --bsr12 --lazy --ohh

(found May 4, 2017)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 16384  --mls16384
block splitting recursion 12  --bsr12
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 2 more bytes (126639 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://builds.emberjs.com/tags/v2.12.2/ember.min.js --location | md5sum
d043d06dcb9878735e600e9df496d93b  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.12.2.min.zopfli.js.gz | md5sum
d043d06dcb9878735e600e9df496d93b  -

SHA1:
curl --silent --compressed http://builds.emberjs.com/tags/v2.12.2/ember.min.js --location | sha1sum
125e0b3d6844ba7a3d74c4134d44295cb53e1e7f  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.12.2.min.zopfli.js.gz | sha1sum
125e0b3d6844ba7a3d74c4134d44295cb53e1e7f  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 164358 bytes d043d06dcb9878735e600e9df496d93b May 3, 2017 @ 07:19
cdnjs 134051 bytes d043d06dcb9878735e600e9df496d93b April 28, 2017 @ 00:18

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

Other Versions

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

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
126641 bytes -2 bytes zopfli --i1000000 --mls16384 --bsr12 --lazy --ohh May 4, 2017 @ 10:01
126643 bytes -3 bytes zopfli --i100000 --mls16384 --bsr12 --lazy --ohh May 2, 2017 @ 13:10
126646 bytes -2 bytes zopfli --i10000 --mls16384 --bsr12 --lazy --ohh April 29, 2017 @ 03:28
126648 bytes -2 bytes zopfli --i10000 --mls16384 --bsr6 --lazy --ohh April 29, 2017 @ 02:16
126650 bytes -9 bytes zopfli --i10000 --mls16384 --bsr22 --lazy --ohh April 29, 2017 @ 01:59
126659 bytes -1 byte zopfli --i1000 --mls16384 --bsr4 --lazy --ohh April 28, 2017 @ 16:10
126660 bytes -1 byte zopfli --i1000 --mls16384 --bsr22 --lazy --ohh April 28, 2017 @ 16:03
126661 bytes -28 bytes zopfli --i1000 --mls16384 --bsr17 --lazy --ohh April 28, 2017 @ 15:33
126689 bytes zopfli --i100 --mls16384 --bsr12 --lazy --ohh April 28, 2017 @ 14:32

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

Most recent activity on May 4, 2017 @ 11:16.

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
126796 126797 126798 126799 126799 126798 126795 126795 126766 126750 126684 126798 126796 126693 126798
126764 126697 126758 126799 126799 126798 126795 126795 126830 126656 126655 126696 126796 126651 126798
126698 126684 126723 126722 126724 126724 126723 126725 126692 126660 126662 126660 126796 126644 126723
126698 126691 126686 126799 126700 126699 126795 126729 126687 126657 126661 126662 126796 126661 126720
126683 126699 126724 126727 126725 126722 126725 126760 126690 126661 126664 126694 126696 126643 126720
126706 126696 126692 126721 126726 126731 126731 126740 126696 126657 126678 126694 126692 126686 126720
126690 126689 126725 126732 126729 126729 126724 126726 126689 126681 126674 126659 126690 126655 126720
126688 126690 126723 126722 126738 126724 126721 126727 126696 126681 126677 126656 126689 126657 126720
126722 126719 126721 126724 126724 126725 126725 126760 126704 126685 126683 126661 126692 126641 126720
126695 126686 126730 126728 126729 126729 126729 126726 126703 126693 126670 126655 126693 126657 126720
126722 126691 126690 126725 126685 126691 126721 126725 126708 126673 126697 126659 126725 126657 126720
126733 126693 126700 126731 126703 126702 126730 126730 126708 126686 126698 126668 126693 126657 126726
126726 126694 126689 126726 126721 126704 126726 126725 126688 126677 126666 126657 126725 126656 126720
126733 126701 126700 126730 126738 126701 126731 126723 126707 126674 126698 126658 126746 126652 126720
126693 126688 126701 126730 126690 126729 126724 126723 126695 126688 126663 126665 126691 126706 126720
126685 126685 126760 126731 126721 126723 126723 126721 126706 126703 126686 126659 126656 126656 126720
126730 126725 126724 126731 126730 126730 126762 126732 126709 126688 126672 126658 126692 126658 126721
126730 126691 126702 126730 126733 126705 126727 126727 126687 126685 126682 126694 126688 126658 126720
126687 126670 126695 126721 126738 126691 126724 126727 126687 126686 126680 126658 126689 126650 126720
126726 126660 126689 126725 126736 126721 126725 126723 126696 126681 126673 126661 126692 126657 126720
126692 126692 126724 126725 126724 126691 126725 126725 126701 126686 126673 126657 126692 126656 126720
126688 126688 126726 126721 126722 126692 126725 126722 126686 126676 126683 126658 126693 126657 126721
126669 126669 126681 126731 126724 126687 126724 126723 126694 126673 126655 126662 126656 126656 126720

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 126689 bytes 100%
1,000 126659 bytes -30 bytes 100%
10,000 126646 bytes -13 bytes 100%
100,000 126643 bytes -3 bytes 0.87%
1,000,000 126641 bytes -2 bytes 0.58%
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
126734 bytes +93 bytes (+0.07%) +28 bytes
126773 bytes +132 bytes (+0.10%) +67 bytes
126799 bytes +158 bytes (+0.12%) +93 bytes
126792 bytes +151 bytes (+0.12%) +86 bytes
126735 bytes +94 bytes (+0.07%) +29 bytes
126706 bytes +65 bytes (+0.05%)
126750 bytes +109 bytes (+0.09%) +44 bytes
126792 bytes +151 bytes (+0.12%) +86 bytes
126807 bytes +166 bytes (+0.13%) +101 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 85688 bytes -40953 bytes (-32.34%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 92720 bytes -33921 bytes (-26.79%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 96509 bytes -30132 bytes (-23.79%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 106415 bytes -20226 bytes (-15.97%)
Brotli (Wikipedia) brotli brotli -q 11 110090 bytes -16551 bytes (-13.07%)
LZMA2 (Wikipedia) xz xz -9 111956 bytes -14685 bytes (-11.60%)
ZSTD (Wikipedia) zstd zstd -19 115375 bytes -11266 bytes (-8.90%)

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 2017.
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