Choose a version:
27% The original file has 1672934 bytes (1,633.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 445907 bytes (435.5k, 27%).

After GZIP compression these minified files vary in size:
Boot
  140702 bytes (137.4k)
CDN
gzip -6 (default)
  114116 bytes (111.4k)
local copy
gzip -9
  113713 bytes (111.0k)
local copy
cdnhttps
  113552 bytes (110.9k)
CDN
cdnjs
  113552 bytes (110.9k)
CDN
7zip -mx=9 -tgzip
  109882 bytes (107.3k)
local copy
libdeflate -12
  109800 bytes (107.2k)
local copy
pigz -11 -n
  109685 bytes (107.1k)
local copy
kzip -s0 -rn -b5
  109607 bytes (107.0k)
local copy
Zopfli
  109471 bytes (106.9k)
local copy
Zopfli (defluff)
  109468 bytes (106.9k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-2.2.1.min.js (or via HTTPS)

You will automatically get the smallest Ember 2.2.1 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 4081 bytes by using my Ember 2.2.1 Zopfli version instead of the best available CDN (3.73% smaller than cdnjs, 109471 vs. 113552 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 --mls32 --bsr7 --lazy --ohh

(found January 19, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 32  --mls32
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 (109468 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://builds.emberjs.com/tags/v2.2.1/ember.min.js --location | md5sum
ef8e7a1c984440b690b94a207d88c94f  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-2.2.1.min.zopfli.js.gz | md5sum
ef8e7a1c984440b690b94a207d88c94f  -

SHA1:
curl --silent --compressed https://builds.emberjs.com/tags/v2.2.1/ember.min.js --location | sha1sum
1ad93a325f7402b4c076e29acf8d315b9a90cb65  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-2.2.1.min.zopfli.js.gz | sha1sum
1ad93a325f7402b4c076e29acf8d315b9a90cb65  -

CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Boot 140702 bytes fe002500c45b6c63edee36202cd34d21 < },to:function(e){var t=this;return new t(e,void 0)}}),e.Bi [...]
< }function A(e,t,r,n){G.test(t)&&n.writeBindings(t,r)}funct [...]
> },to:function(e){var t=this;return new t(e,void 0)}}),e.Bi [...]
> G.test(t)&&n.writeBindings(t,r)}function O(e,t,r){var n=fu [...]
< id:"ember-runtime.ext-function",until:"3.0.0"},o._observes [...]
> id:"ember-runtime.ext-function",until:"3.0.0"},o._observes [...]
< instrumentDisplay:"Ember.SelectOption",tagName:"option",at [...]
> instrumentDisplay:"Ember.SelectOption",tagName:"option",at [...]
January 16, 2016 @ 15:05
cdnhttps 113552 bytes fe002500c45b6c63edee36202cd34d21 < },to:function(e){var t=this;return new t(e,void 0)}}),e.Bi [...]
< }function A(e,t,r,n){G.test(t)&&n.writeBindings(t,r)}funct [...]
> },to:function(e){var t=this;return new t(e,void 0)}}),e.Bi [...]
> G.test(t)&&n.writeBindings(t,r)}function O(e,t,r){var n=fu [...]
< id:"ember-runtime.ext-function",until:"3.0.0"},o._observes [...]
> id:"ember-runtime.ext-function",until:"3.0.0"},o._observes [...]
< instrumentDisplay:"Ember.SelectOption",tagName:"option",at [...]
> instrumentDisplay:"Ember.SelectOption",tagName:"option",at [...]
November 22, 2016 @ 16:33
cdnjs 113552 bytes fe002500c45b6c63edee36202cd34d21 < },to:function(e){var t=this;return new t(e,void 0)}}),e.Bi [...]
< }function A(e,t,r,n){G.test(t)&&n.writeBindings(t,r)}funct [...]
> },to:function(e){var t=this;return new t(e,void 0)}}),e.Bi [...]
> G.test(t)&&n.writeBindings(t,r)}function O(e,t,r){var n=fu [...]
< id:"ember-runtime.ext-function",until:"3.0.0"},o._observes [...]
> id:"ember-runtime.ext-function",until:"3.0.0"},o._observes [...]
< instrumentDisplay:"Ember.SelectOption",tagName:"option",at [...]
> instrumentDisplay:"Ember.SelectOption",tagName:"option",at [...]
January 15, 2016 @ 07:02

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
109471 bytes -7 bytes zopfli --i1000000 --mls32 --bsr7 --lazy --ohh January 19, 2016 @ 21:29
109478 bytes -9 bytes zopfli --i100000 --mls32 --bsr7 --lazy --ohh January 18, 2016 @ 16:36
109487 bytes -12 bytes zopfli --i10000 --mls32 --bsr7 --lazy --ohh January 18, 2016 @ 09:21
109499 bytes -12 bytes zopfli --i1000 --mls32 --bsr7 --lazy --ohh January 17, 2016 @ 22:16
109511 bytes -2 bytes zopfli --i1000 --mls32 --bsr40 --lazy --ohh January 17, 2016 @ 21:39
109513 bytes -3 bytes zopfli --i1000 --mls2 --bsr13 --lazy --ohh January 17, 2016 @ 21:21
109516 bytes zopfli --i100 --mls32 --bsr7 --lazy --ohh January 17, 2016 @ 21:03

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
109543 109541 109676 109683 109551 109541 109606 109522 109525 109605 109616 109684 109674 109611 109689
109519 109532 109519 109539 109529 109620 109610 109544 109550 109609 109542 109634 109608 109559 109630
109541 109540 109539 109546 109522 109522 109509 109516 109518 109531 109537 109516 109514 109518 109608
109623 109623 109632 109622 109471 109634 109711 109515 109536 109529 109515 109526 109535 109620 109616
109616 109622 109623 109622 109631 109501 109711 109518 109518 109530 109523 109532 109524 109628 109631
109616 109623 109623 109619 109519 109616 109711 109531 109523 109519 109523 109535 109611 109627 109616
109507 109628 109623 109628 109518 109616 109712 109546 109533 109533 109524 109526 109526 109629 109616
109623 109621 109615 109631 109527 109622 109711 109527 109520 109519 109522 109537 109520 109615 109631
109503 109623 109632 109622 109502 109616 109615 109530 109515 109514 109524 109531 109523 109627 109631
109502 109620 109632 109629 109499 109615 109711 109529 109531 109527 109554 109608 109523 109628 109616
109623 109622 109618 109634 109529 109631 109712 109521 109514 109532 109528 109536 109613 109628 109624
109623 109622 109632 109632 109515 109514 109712 109522 109531 109533 109524 109568 109523 109628 109617
109622 109621 109623 109622 109519 109489 109712 109522 109518 109518 109524 109537 109511 109627 109616
109631 109639 109623 109631 109499 109617 109626 109535 109519 109511 109524 109536 109522 109629 109615
109617 109616 109625 109630 109520 109528 109633 109522 109524 109516 109518 109535 109515 109627 109616
109489 109630 109629 109622 109488 109634 109524 109514 109515 109523 109618 109621 109606 109629 109616
109503 109622 109623 109622 109529 109634 109522 109517 109529 109527 109519 109619 109522 109629 109631
109623 109622 109615 109628 109616 109634 109523 109538 109527 109527 109527 109531 109516 109615 109613
109503 109620 109615 109622 109634 109634 109712 109511 109536 109520 109525 109530 109539 109627 109616
109623 109622 109615 109628 109531 109519 109622 109519 109523 109520 109519 109528 109514 109628 109613
109503 109620 109623 109616 109635 109520 109712 109539 109530 109520 109519 109527 109522 109627 109620
109622 109631 109631 109622 109526 109631 109630 109515 109517 109514 109521 109531 109511 109628 109617
109616 109622 109615 109622 109499 109630 109622 109558 109535 109510 109517 109536 109521 109627 109616

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 109516 bytes 100%
1,000 109499 bytes -17 bytes 100%
10,000 109487 bytes -12 bytes 100%
100,000 109478 bytes -9 bytes 1.16%
1,000,000 109471 bytes -7 bytes 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
109669 bytes +198 bytes (+0.18%) +62 bytes
109621 bytes +150 bytes (+0.14%) +14 bytes
109673 bytes +202 bytes (+0.18%) +66 bytes
109690 bytes +219 bytes (+0.20%) +83 bytes
109643 bytes +172 bytes (+0.16%) +36 bytes
109607 bytes +136 bytes (+0.12%)
109646 bytes +175 bytes (+0.16%) +39 bytes
109611 bytes +140 bytes (+0.13%) +4 bytes
109665 bytes +194 bytes (+0.18%) +58 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 74716 bytes -34755 bytes (-31.75%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 79919 bytes -29552 bytes (-27.00%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 86024 bytes -23447 bytes (-21.42%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 90877 bytes -18594 bytes (-16.99%)
Brotli (Wikipedia) brotli brotli -q 11 94978 bytes -14493 bytes (-13.24%)
LZMA2 (Wikipedia) xz xz -9 97120 bytes -12351 bytes (-11.28%)
Zstandard (Wikipedia) zstd zstd -19 99879 bytes -9592 bytes (-8.76%)

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