Choose a version:
24% The original file has 1032179 bytes (1,008.0k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 248956 bytes (243.1k, 24%).

After GZIP compression these minified files vary in size:
Boot
  84902 bytes (82.9k)
CDN, direct link
Baidu
  70592 bytes (68.9k)
CDN, direct link
cdnjs
  70572 bytes (68.9k)
CDN, direct link
gzip -6 (default)
  69653 bytes (68.0k)
local copy
cdnhttps
  69565 bytes (67.9k)
CDN, direct link
gzip -9
  69303 bytes (67.7k)
local copy
7zip -mx=9 -tgzip
  66855 bytes (65.3k)
local copy
pigz -11 -n
  66660 bytes (65.1k)
local copy
libdeflate -12
  66651 bytes (65.1k)
local copy
kzip -s0 -rn -b1
  66624 bytes (65.1k)
local copy
Zopfli
  66546 bytes (65.0k)
local copy
Zopfli (defluff)
  66545 bytes (65.0k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-1.2.2.min.js

You will automatically get the smallest Ember 1.2.2 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 3019 bytes by using my Ember 1.2.2 Zopfli version instead of the best available CDN (4.54% smaller than cdnhttps, 66546 vs. 69565 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 --mls4096 --bsr20 --lazy --ohh

(found July 25, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 4096  --mls4096
block splitting recursion 20  --bsr20
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 (66545 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://builds.emberjs.com/tags/v1.2.2/ember.min.js --location | md5sum
c91653641269b9de1ea1746157d0ac01  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-1.2.2.min.zopfli.js.gz | md5sum
c91653641269b9de1ea1746157d0ac01  -

SHA1:
curl --silent --compressed http://builds.emberjs.com/tags/v1.2.2/ember.min.js --location | sha1sum
221bc3324647c59c2381cf47b55dd5418fcd7953  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-1.2.2.min.zopfli.js.gz | sha1sum
221bc3324647c59c2381cf47b55dd5418fcd7953  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 84902 bytes c91653641269b9de1ea1746157d0ac01 March 19, 2015 @ 17:51
cdnjs 70572 bytes c91653641269b9de1ea1746157d0ac01 February 8, 2014 @ 18:00
cdnhttps 69565 bytes c91653641269b9de1ea1746157d0ac01 December 24, 2015 @ 07:33

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Baidu 70592 bytes 7f33d3b0d3f11c4b50ba59d86dc797db only whitespaces differ June 5, 2014 @ 10:05

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

Other Versions

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

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
66546 bytes -2 bytes zopfli --i100000 --mls4096 --bsr20 --lazy --ohh July 25, 2016 @ 11:49
66548 bytes -1 byte zopfli --i100000 --mls512 --bsr4 --lazy --ohh November 21, 2015 @ 11:02
66549 bytes -1 byte zopfli --i100000 --mls256 --bsr4 --lazy --ohh November 21, 2015 @ 09:34
66550 bytes -5 bytes zopfli --i10000 --mls512 --bsr4 --lazy --ohh October 14, 2015 @ 10:36
66555 bytes -1 byte zopfli --i1000 --mls512 --bsr4 --lazy --ohh September 11, 2015 @ 02:05
66556 bytes -14 bytes zopfli --i1000 --mls512 --bsr12 --lazy --ohh September 11, 2015 @ 02:03
66570 bytes -11 bytes zopfli --i1000 --mls512 --bsr2 --lazy --ohh September 11, 2015 @ 02:01
66581 bytes zopfli --i100 --mls512 --bsr2 --lazy --ohh September 10, 2015 @ 13:54

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

Most recent activity on March 27, 2017 @ 16:27.

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
66555 66556 66555 66555 66555 66553 66553 66553 66555 66554 66554 66554 66556 66556 66552
66558 66558 66557 66554 66554 66556 66552 66549 66548 66551 66550 66549 66553 66553 66554
66558 66554 66555 66552 66554 66552 66560 66553 66548 66551 66553 66550 66558 66553 66556
66558 66552 66556 66550 66556 66557 66556 66550 66548 66551 66552 66551 66551 66561 66556
66554 66555 66553 66554 66554 66557 66558 66557 66550 66552 66552 66552 66554 66564 66554
66553 66553 66553 66556 66554 66553 66560 66550 66556 66550 66552 66552 66552 66556 66564
66557 66557 66555 66557 66551 66554 66559 66550 66548 66551 66551 66551 66556 66564 66554
66554 66555 66551 66551 66552 66551 66558 66557 66548 66551 66551 66551 66556 66555 66552
66554 66554 66553 66551 66551 66557 66560 66555 66553 66551 66552 66546 66555 66562 66554
66554 66555 66557 66551 66554 66555 66559 66550 66548 66551 66552 66549 66558 66565 66554
66557 66554 66555 66551 66551 66553 66559 66554 66550 66551 66551 66552 66553 66557 66555
66553 66554 66553 66551 66551 66555 66560 66550 66550 66551 66553 66549 66553 66565 66556
66557 66554 66554 66551 66555 66556 66560 66550 66550 66551 66552 66552 66550 66561 66551
66556 66555 66554 66552 66551 66552 66558 66550 66548 66551 66552 66550 66555 66561 66554
66549 66555 66549 66551 66553 66552 66550 66556 66551 66551 66551 66548 66555 66561 66554
66549 66555 66555 66550 66558 66550 66560 66550 66548 66550 66552 66550 66553 66561 66553
66551 66548 66559 66551 66550 66558 66557 66550 66553 66553 66552 66546 66554 66561 66553
66558 66555 66558 66551 66552 66557 66556 66550 66552 66551 66552 66549 66555 66562 66554
66556 66555 66553 66554 66552 66556 66560 66550 66548 66550 66552 66552 66555 66561 66555
66558 66555 66558 66557 66552 66557 66560 66550 66548 66550 66553 66551 66556 66563 66556
66553 66558 66553 66551 66551 66557 66559 66559 66551 66551 66553 66552 66554 66561 66553
66552 66557 66555 66551 66558 66557 66560 66551 66548 66550 66553 66550 66554 66556 66554
66557 66554 66553 66551 66559 66552 66559 66557 66548 66550 66551 66551 66555 66561 66554

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 66573 bytes 100%
1,000 66555 bytes -18 bytes 100%
10,000 66548 bytes -7 bytes 100%
100,000 66546 bytes -2 bytes 5.80%
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
66671 bytes +125 bytes (+0.19%) +47 bytes
66624 bytes +78 bytes (+0.12%)
66672 bytes +126 bytes (+0.19%) +48 bytes
66683 bytes +137 bytes (+0.21%) +59 bytes
66673 bytes +127 bytes (+0.19%) +49 bytes
66725 bytes +179 bytes (+0.27%) +101 bytes
66751 bytes +205 bytes (+0.31%) +127 bytes
66792 bytes +246 bytes (+0.37%) +168 bytes
66803 bytes +257 bytes (+0.39%) +179 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 48365 bytes -18181 bytes (-27.32%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 51225 bytes -15321 bytes (-23.02%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 55118 bytes -11428 bytes (-17.17%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 58189 bytes -8357 bytes (-12.56%)
Brotli (Wikipedia) brotli brotli -q 11 59367 bytes -7179 bytes (-10.79%)
LZMA2 (Wikipedia) xz xz -9 61116 bytes -5430 bytes (-8.16%)
ZSTD (Wikipedia) zstd zstd -19 62715 bytes -3831 bytes (-5.76%)

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 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