Choose a version:
26% The original file has 1614047 bytes (1,576.2k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 419394 bytes (409.6k, 26%).

After GZIP compression these minified files vary in size:
Boot
  136594 bytes (133.4k)
CDN
cdnjs
  112019 bytes (109.4k)
CDN
gzip -6 (default)
  110439 bytes (107.9k)
local copy
gzip -9
  110086 bytes (107.5k)
local copy
cdnhttps
  109895 bytes (107.3k)
CDN
7zip -mx=9 -tgzip
  106262 bytes (103.8k)
local copy
libdeflate -12
  106122 bytes (103.6k)
local copy
pigz -11 -n
  106121 bytes (103.6k)
local copy
kzip -s0 -rn -b0
  105913 bytes (103.4k)
local copy
Zopfli
  105871 bytes (103.4k)
local copy
Zopfli (defluff)
  105870 bytes (103.4k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-2.8.1.min.js

You will automatically get the smallest Ember 2.8.1 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 4024 bytes by using my Ember 2.8.1 Zopfli version instead of the best available CDN (3.80% smaller than cdnhttps, 105871 vs. 109895 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 --mls4 --bsr2 --lazy --ohh

(found September 16, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 4  --mls4
block splitting recursion 2  --bsr2
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 (105870 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://builds.emberjs.com/tags/v2.8.1/ember.min.js --location | md5sum
ce043075e9a25ec31ac71d0745536f43  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.8.1.min.zopfli.js.gz | md5sum
ce043075e9a25ec31ac71d0745536f43  -

SHA1:
curl --silent --compressed http://builds.emberjs.com/tags/v2.8.1/ember.min.js --location | sha1sum
76e52227e86c983e441c50d6ad9d88635523073c  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.8.1.min.zopfli.js.gz | sha1sum
76e52227e86c983e441c50d6ad9d88635523073c  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 136594 bytes ce043075e9a25ec31ac71d0745536f43 September 21, 2016 @ 17:02
cdnjs 112019 bytes ce043075e9a25ec31ac71d0745536f43 September 15, 2016 @ 05:46
cdnhttps 109895 bytes ce043075e9a25ec31ac71d0745536f43 November 22, 2016 @ 16:33

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
105871 bytes -1 byte zopfli --i100000 --mls4 --bsr2 --lazy --ohh September 16, 2016 @ 12:58
105872 bytes -1 byte zopfli --i10000 --mls256 --bsr12 --lazy --ohh September 15, 2016 @ 15:29
105873 bytes -1 byte zopfli --i10000 --mls128 --bsr7 --lazy --ohh September 15, 2016 @ 11:57
105874 bytes -9 bytes zopfli --i10000 --mls32 --bsr6 --lazy --ohh September 15, 2016 @ 11:44
105883 bytes -1 byte zopfli --i1000 --mls128 --bsr20 --lazy --ohh September 15, 2016 @ 10:52
105884 bytes -12 bytes zopfli --i1000 --mls16 --bsr18 --lazy --ohh September 15, 2016 @ 10:51
105896 bytes zopfli --i100 --mls16 --bsr18 --lazy --ohh September 15, 2016 @ 10:17

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
105874 105871 105879 105904 105935 105879 105879 105879 105878 105879 105877 105879 105884 105876 105883
105876 105878 105873 105935 105874 105874 105874 105874 105874 105876 105877 105874 105885 105884 105885
105878 105874 105874 105876 105874 105874 105873 105874 105874 105874 105874 105876 105886 105883 105883
105876 105876 105874 105874 105874 105874 105873 105874 105872 105876 105881 105874 105883 105882 105882
105878 105901 105879 105876 105879 105873 105874 105874 105872 105876 105874 105874 105884 105882 105883
105873 105874 105874 105873 105874 105873 105876 105874 105873 105875 105874 105873 105881 105883 105883
105879 105874 105874 105873 105874 105873 105875 105874 105874 105875 105874 105873 105882 105883 105884
105874 105874 105874 105874 105874 105873 105873 105873 105872 105876 105874 105873 105881 105882 105883
105874 105871 105874 105873 105874 105873 105873 105872 105873 105875 105874 105874 105882 105883 105882
105873 105874 105874 105873 105874 105874 105873 105874 105874 105874 105874 105874 105884 105884 105884
105873 105874 105874 105902 105874 105874 105873 105874 105874 105873 105874 105874 105883 105882 105884
105873 105874 105874 105873 105874 105874 105873 105874 105874 105876 105881 105874 105882 105881 105883
105874 105874 105873 105874 105873 105873 105874 105874 105872 105878 105879 105880 105882 105886 105884
105873 105874 105874 105874 105873 105873 105873 105875 105874 105878 105878 105879 105883 105883 105883
105874 105874 105874 105873 105874 105873 105873 105874 105873 105875 105873 105873 105884 105882 105884
105874 105874 105874 105873 105874 105873 105873 105873 105873 105879 105879 105874 105884 105883 105883
105878 105906 105878 105873 105874 105873 105873 105874 105873 105876 105878 105879 105884 105885 105886
105878 105877 105874 105873 105878 105873 105876 105873 105873 105876 105879 105873 105884 105882 105882
105873 105874 105873 105873 105873 105873 105873 105874 105874 105876 105873 105873 105884 105883 105882
105873 105874 105874 105874 105873 105874 105874 105874 105874 105876 105878 105873 105884 105886 105886
105873 105874 105874 105873 105873 105874 105873 105872 105872 105876 105874 105873 105882 105883 105884
105873 105874 105874 105873 105873 105873 105873 105874 105874 105876 105875 105873 105884 105883 105883
105874 105871 105874 105873 105873 105873 105873 105874 105873 105875 105873 105873 105883 105882 105883

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 105896 bytes 100%
1,000 105883 bytes -13 bytes 100%
10,000 105872 bytes -11 bytes 100%
100,000 105871 bytes -1 byte 2.90%
1,000,000 105871 bytes 0.87%
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
105913 bytes +42 bytes (+0.04%)
105918 bytes +47 bytes (+0.04%) +5 bytes
105952 bytes +81 bytes (+0.08%) +39 bytes
105922 bytes +51 bytes (+0.05%) +9 bytes
105968 bytes +97 bytes (+0.09%) +55 bytes
106022 bytes +151 bytes (+0.14%) +109 bytes
106064 bytes +193 bytes (+0.18%) +151 bytes
106103 bytes +232 bytes (+0.22%) +190 bytes
106117 bytes +246 bytes (+0.23%) +204 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 72875 bytes -32996 bytes (-31.17%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 77790 bytes -28081 bytes (-26.52%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 83486 bytes -22385 bytes (-21.14%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 88527 bytes -17344 bytes (-16.38%)
Brotli (Wikipedia) brotli brotli -q 11 92732 bytes -13139 bytes (-12.41%)
LZMA2 (Wikipedia) xz xz -9 94852 bytes -11019 bytes (-10.41%)
ZSTD (Wikipedia) zstd zstd -19 97469 bytes -8402 bytes (-7.94%)

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