Choose a version:
26% The original file has 1654421 bytes (1,615.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 428693 bytes (418.6k, 26%).

After GZIP compression these minified files vary in size:
Boot
  139356 bytes (136.1k)
CDN, direct link
cdnjs
  114353 bytes (111.7k)
CDN, direct link
gzip -6 (default)
  112723 bytes (110.1k)
local copy
gzip -9
  112361 bytes (109.7k)
local copy
cdnhttps
  112174 bytes (109.5k)
CDN, direct link
7zip -mx=9 -tgzip
  108479 bytes (105.9k)
local copy
pigz -11 -n
  108293 bytes (105.8k)
local copy
libdeflate -12
  108200 bytes (105.7k)
local copy
kzip -s0 -rn -b0
  108100 bytes (105.6k)
local copy
Zopfli
  108057 bytes (105.5k)
local copy
Zopfli (defluff)
  108054 bytes (105.5k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-2.7.1.min.js

You will automatically get the smallest Ember 2.7.1 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 4117 bytes by using my Ember 2.7.1 Zopfli version instead of the best available CDN (3.81% smaller than cdnhttps, 108057 vs. 112174 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 --mls8 --bsr7 --lazy --ohh

(found August 18, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8  --mls8
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 (108054 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://builds.emberjs.com/tags/v2.7.1/ember.min.js --location | md5sum
1805ef7bece3110ef1b62abe0576f2a6  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.7.1.min.zopfli.js.gz | md5sum
1805ef7bece3110ef1b62abe0576f2a6  -

SHA1:
curl --silent --compressed http://builds.emberjs.com/tags/v2.7.1/ember.min.js --location | sha1sum
6028396bbb43b45329fc2c8cec0b031af648cf2c  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.7.1.min.zopfli.js.gz | sha1sum
6028396bbb43b45329fc2c8cec0b031af648cf2c  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 139356 bytes 1805ef7bece3110ef1b62abe0576f2a6 August 20, 2016 @ 16:17
cdnjs 114353 bytes 1805ef7bece3110ef1b62abe0576f2a6 August 16, 2016 @ 05:16
cdnhttps 112174 bytes 1805ef7bece3110ef1b62abe0576f2a6 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:

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
108057 bytes -4 bytes zopfli --i1000000 --mls8 --bsr7 --lazy --ohh August 18, 2016 @ 06:46
108061 bytes -2 bytes zopfli --i100000 --mls64 --bsr4 --lazy --ohh August 17, 2016 @ 01:29
108063 bytes -5 bytes zopfli --i100000 --mls32768 --bsr18 --lazy --ohh August 16, 2016 @ 12:17
108068 bytes -1 byte zopfli --i10000 --mls32768 --bsr18 --lazy --ohh August 16, 2016 @ 10:14
108069 bytes -17 bytes zopfli --i1000 --mls32768 --bsr18 --lazy --ohh August 16, 2016 @ 09:59
108086 bytes zopfli --i100 --mls32768 --bsr18 --lazy --ohh August 16, 2016 @ 09:43

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
108069 108071 108078 108074 108082 108074 108075 108074 108074 108072 108074 108079 108074 108081 108072
108070 108070 108070 108071 108082 108061 108074 108070 108080 108080 108077 108069 108084 108082 108084
108072 108070 108069 108071 108069 108070 108071 108072 108071 108074 108077 108095 108082 108082 108079
108072 108071 108057 108070 108068 108072 108071 108069 108070 108071 108076 108069 108081 108081 108079
108072 108071 108069 108071 108068 108072 108072 108069 108070 108071 108065 108068 108084 108082 108082
108069 108071 108068 108071 108067 108071 108072 108069 108071 108071 108071 108081 108084 108080 108080
108072 108071 108075 108071 108069 108071 108071 108069 108082 108071 108076 108070 108071 108081 108080
108069 108071 108069 108068 108074 108075 108071 108069 108071 108062 108076 108069 108084 108081 108084
108072 108071 108072 108071 108071 108071 108071 108072 108078 108069 108076 108069 108084 108081 108084
108069 108071 108069 108071 108082 108071 108071 108069 108071 108069 108075 108070 108082 108081 108085
108072 108070 108072 108071 108069 108071 108071 108069 108071 108071 108079 108080 108083 108079 108085
108071 108071 108072 108068 108068 108071 108071 108069 108071 108071 108076 108071 108082 108075 108080
108072 108071 108124 108071 108070 108071 108064 108112 108076 108082 108078 108080 108070 108081 108080
108072 108071 108069 108072 108070 108071 108064 108078 108076 108062 108071 108079 108084 108082 108085
108070 108071 108071 108071 108069 108072 108072 108069 108071 108071 108075 108070 108079 108081 108063
108069 108071 108068 108071 108069 108071 108071 108072 108082 108081 108075 108070 108077 108081 108081
108069 108071 108069 108068 108068 108072 108071 108070 108070 108075 108076 108079 108074 108082 108080
108072 108070 108069 108070 108068 108072 108064 108070 108070 108071 108075 108081 108082 108082 108085
108072 108070 108063 108068 108068 108071 108071 108072 108070 108067 108076 108071 108082 108080 108082
108072 108071 108068 108071 108069 108071 108078 108070 108071 108071 108071 108081 108081 108080 108084
108072 108070 108072 108071 108068 108071 108076 108069 108070 108072 108076 108077 108071 108080 108083
108071 108071 108072 108071 108069 108072 108071 108071 108080 108071 108076 108079 108083 108154 108085
108070 108070 108063 108069 108074 108074 108071 108069 108071 108069 108076 108069 108085 108082 108082

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 108086 bytes 100%
1,000 108069 bytes -17 bytes 100%
10,000 108066 bytes -3 bytes 100%
100,000 108061 bytes -5 bytes 3.48%
1,000,000 108057 bytes -4 bytes 1.16%
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
108100 bytes +43 bytes (+0.04%)
108107 bytes +50 bytes (+0.05%) +7 bytes
108142 bytes +85 bytes (+0.08%) +42 bytes
108107 bytes +50 bytes (+0.05%) +7 bytes
108154 bytes +97 bytes (+0.09%) +54 bytes
108209 bytes +152 bytes (+0.14%) +109 bytes
108262 bytes +205 bytes (+0.19%) +162 bytes
108290 bytes +233 bytes (+0.22%) +190 bytes
108339 bytes +282 bytes (+0.26%) +239 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 74105 bytes -33952 bytes (-31.42%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 79205 bytes -28852 bytes (-26.70%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 85685 bytes -22372 bytes (-20.70%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 90292 bytes -17765 bytes (-16.44%)
Brotli (Wikipedia) brotli brotli -q 11 94288 bytes -13769 bytes (-12.74%)
LZMA2 (Wikipedia) xz xz -9 96456 bytes -11601 bytes (-10.74%)
ZSTD (Wikipedia) zstd zstd -19 99096 bytes -8961 bytes (-8.29%)

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