Choose a version:
23% The original file has 1549447 bytes (1,513.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 353572 bytes (345.3k, 23%).

After GZIP compression these minified files vary in size:
Boot
  121370 bytes (118.5k)
CDN, direct link
cdnjs
  100990 bytes (98.6k)
CDN, direct link
gzip -6 (default)
  99714 bytes (97.4k)
local copy
cdnhttps
  99611 bytes (97.3k)
CDN, direct link
gzip -9
  99426 bytes (97.1k)
local copy
jsdelivr
  99377 bytes (97.0k)
CDN, direct link
7zip -mx=9 -tgzip
  96101 bytes (93.8k)
local copy
pigz -11 -n
  95921 bytes (93.7k)
local copy
libdeflate -12
  95920 bytes (93.7k)
local copy
kzip -s0 -rn -b1
  95763 bytes (93.5k)
local copy
Zopfli
  95718 bytes (93.5k)
local copy
Zopfli (defluff)
  95717 bytes (93.5k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-1.8.1.min.js

You will automatically get the smallest Ember 1.8.1 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 3659 bytes by using my Ember 1.8.1 Zopfli version instead of the best available CDN (3.82% smaller than jsdelivr, 95718 vs. 99377 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 --mls2 --bsr7 --lazy --ohh

(found November 22, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 2  --mls2
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 1 more byte (95717 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://builds.emberjs.com/tags/v1.8.1/ember.min.js --location | md5sum
9035c6514b9d40902f9f5b62b59e373e  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-1.8.1.min.zopfli.js.gz | md5sum
9035c6514b9d40902f9f5b62b59e373e  -

SHA1:
curl --silent --compressed http://builds.emberjs.com/tags/v1.8.1/ember.min.js --location | sha1sum
a0f8537ced01eedf908876b8120dfa291507affb  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-1.8.1.min.zopfli.js.gz | sha1sum
a0f8537ced01eedf908876b8120dfa291507affb  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 121370 bytes 9035c6514b9d40902f9f5b62b59e373e March 19, 2015 @ 18:36
cdnjs 100990 bytes 9035c6514b9d40902f9f5b62b59e373e November 5, 2014 @ 06:45
cdnhttps 99611 bytes 9035c6514b9d40902f9f5b62b59e373e December 24, 2015 @ 07:33
jsdelivr 99377 bytes 9035c6514b9d40902f9f5b62b59e373e November 4, 2014 @ 23:34

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
95718 bytes -1 byte zopfli --i100000 --mls2 --bsr7 --lazy --ohh November 22, 2015 @ 16:51
95719 bytes -2 bytes zopfli --i100000 --mls2048 --bsr14 --lazy --ohh November 22, 2015 @ 03:06
95721 bytes -2 bytes zopfli --i10000 --mls4 --bsr8 --lazy --ohh November 21, 2015 @ 17:20
95723 bytes -1 byte zopfli --i1000 --mls4 --bsr8 --lazy --ohh September 21, 2015 @ 23:30
95724 bytes -2 bytes zopfli --i1000 --mls512 --bsr9 --lazy --ohh September 10, 2015 @ 23:53
95726 bytes -1 byte zopfli --i1000 --mls512 --bsr2 --lazy --ohh September 10, 2015 @ 23:51
95727 bytes -55 bytes zopfli --i1000 --mls512 --bsr4 --lazy --ohh September 10, 2015 @ 23:51
95782 bytes zopfli --i100 --mls4096 --bsr10 --lazy --ohh September 10, 2015 @ 13:50

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

Most recent activity on March 28, 2017 @ 16:43.

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
95728 95728 95729 95728 95734 95727 95726 95726 95725 95725 95725 95726 95725 95737 95740
95728 95732 95731 95726 95728 95732 95733 95731 95724 95730 95726 95724 95726 95742 95727
95725 95726 95726 95727 95725 95725 95725 95728 95722 95726 95724 95725 95733 95738 95731
95718 95729 95726 95728 95729 95726 95728 95746 95719 95728 95724 95725 95733 95738 95725
95720 95719 95725 95726 95728 95729 95725 95731 95725 95726 95724 95725 95733 95739 95732
95722 95722 95722 95725 95725 95726 95725 95730 95719 95724 95725 95724 95730 95738 95725
95725 95726 95727 95726 95728 95730 95726 95733 95726 95725 95724 95719 95737 95737 95729
95725 95726 95727 95725 95726 95725 95727 95733 95724 95728 95725 95724 95739 95738 95729
95722 95722 95724 95726 95732 95731 95730 95730 95732 95730 95724 95726 95737 95760 95730
95725 95724 95725 95728 95729 95724 95728 95733 95726 95729 95719 95724 95728 95739 95729
95727 95727 95726 95728 95729 95729 95726 95725 95725 95725 95719 95725 95730 95739 95735
95725 95719 95726 95731 95728 95729 95722 95732 95724 95728 95724 95725 95728 95739 95728
95728 95725 95719 95725 95728 95732 95722 95730 95724 95725 95724 95724 95734 95738 95730
95725 95726 95725 95728 95729 95728 95725 95725 95724 95725 95719 95732 95730 95738 95733
95725 95726 95725 95727 95726 95726 95726 95724 95725 95724 95723 95724 95734 95738 95759
95725 95728 95724 95728 95726 95725 95730 95733 95726 95725 95724 95718 95732 95738 95729
95725 95724 95728 95726 95724 95728 95728 95732 95725 95729 95724 95726 95727 95737 95734
95725 95729 95725 95729 95724 95728 95725 95724 95725 95724 95719 95721 95738 95739 95729
95725 95725 95725 95728 95731 95726 95728 95725 95725 95725 95724 95724 95729 95739 95759
95725 95724 95725 95725 95729 95726 95725 95733 95725 95725 95724 95730 95729 95739 95729
95722 95729 95728 95728 95726 95727 95728 95730 95732 95724 95724 95729 95733 95736 95731
95725 95722 95729 95729 95724 95730 95728 95726 95727 95725 95724 95724 95733 95739 95728
95726 95726 95725 95728 95728 95728 95730 95738 95724 95725 95725 95726 95729 95738 95734

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 95759 bytes 100%
1,000 95723 bytes -36 bytes 100%
10,000 95721 bytes -2 bytes 100%
100,000 95718 bytes -3 bytes 4.35%
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
95768 bytes +50 bytes (+0.05%) +5 bytes
95763 bytes +45 bytes (+0.05%)
95818 bytes +100 bytes (+0.10%) +55 bytes
95871 bytes +153 bytes (+0.16%) +108 bytes
95848 bytes +130 bytes (+0.14%) +85 bytes
95883 bytes +165 bytes (+0.17%) +120 bytes
95912 bytes +194 bytes (+0.20%) +149 bytes
95856 bytes +138 bytes (+0.14%) +93 bytes
95901 bytes +183 bytes (+0.19%) +138 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 67518 bytes -28200 bytes (-29.46%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 71782 bytes -23936 bytes (-25.01%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 75675 bytes -20043 bytes (-20.94%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 81449 bytes -14269 bytes (-14.91%)
Brotli (Wikipedia) brotli brotli -q 11 84320 bytes -11398 bytes (-11.91%)
LZMA2 (Wikipedia) xz xz -9 86424 bytes -9294 bytes (-9.71%)
ZSTD (Wikipedia) zstd zstd -19 88884 bytes -6834 bytes (-7.14%)

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