Choose a version:
31% The original file has 1601847 bytes (1,564.3k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 488880 bytes (477.4k, 31%).

After GZIP compression these minified files vary in size:
Boot
  151443 bytes (147.9k)
CDN, direct link
cdnjs
  124718 bytes (121.8k)
CDN, direct link
gzip -6 (default)
  123244 bytes (120.4k)
local copy
gzip -9
  122731 bytes (119.9k)
local copy
libdeflate -12
  118512 bytes (115.7k)
local copy
7zip -mx=9 -tgzip
  118477 bytes (115.7k)
local copy
pigz -11 -n
  118359 bytes (115.6k)
local copy
kzip -s0 -rn -b3
  118239 bytes (115.5k)
local copy
Zopfli
  118207 bytes (115.4k)
local copy
Zopfli (defluff)
  118202 bytes (115.4k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-2.15.2.min.js

You will automatically get the smallest Ember 2.15.2 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 6511 bytes by using my Ember 2.15.2 Zopfli version instead of the best available CDN (5.51% smaller than cdnjs, 118207 vs. 124718 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 --mls4096 --bsr16 --lazy --ohh

(found October 7, 2017)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 4096  --mls4096
block splitting recursion 16  --bsr16
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 5 more bytes (118202 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://builds.emberjs.com/tags/v2.15.2/ember.min.js --location | md5sum
ccb07fbf9a36eedd44bb59bd7f00ee90  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.15.2.min.zopfli.js.gz | md5sum
ccb07fbf9a36eedd44bb59bd7f00ee90  -

SHA1:
curl --silent --compressed http://builds.emberjs.com/tags/v2.15.2/ember.min.js --location | sha1sum
5b5de6d147937c03e23ddec21a1dd50102216e6d  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.15.2.min.zopfli.js.gz | sha1sum
5b5de6d147937c03e23ddec21a1dd50102216e6d  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 151443 bytes ccb07fbf9a36eedd44bb59bd7f00ee90 October 11, 2017 @ 21:58
cdnjs 124718 bytes ccb07fbf9a36eedd44bb59bd7f00ee90 October 5, 2017 @ 00:34

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

Other Versions

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

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
118207 bytes -1 byte zopfli --i1000000 --mls4096 --bsr16 --lazy --ohh October 7, 2017 @ 06:42
118208 bytes -1 byte zopfli --i100000 --mls4096 --bsr16 --lazy --ohh October 6, 2017 @ 08:59
118209 bytes -3 bytes zopfli --i100000 --mls4096 --bsr12 --lazy --ohh October 6, 2017 @ 00:00
118212 bytes -14 bytes zopfli --i10000 --mls4096 --bsr12 --lazy --ohh October 5, 2017 @ 21:22
118226 bytes -3 bytes zopfli --i1000 --mls16 --bsr4 --lazy --ohh October 5, 2017 @ 21:09
118229 bytes -5 bytes zopfli --i1000 --mls4096 --bsr12 --lazy --ohh October 5, 2017 @ 20:23
118234 bytes -5 bytes zopfli --i1000 --mls128 --bsr12 --lazy --ohh October 5, 2017 @ 20:21
118239 bytes -6 bytes zopfli --i1000 --mls8 --bsr30 --lazy --ohh October 5, 2017 @ 20:16
118245 bytes zopfli --i100 --mls128 --bsr12 --lazy --ohh October 5, 2017 @ 19:30

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

Most recent activity on October 11, 2017 @ 21:58.

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
118239 118239 118240 118239 118233 118236 118236 118238 118240 118233 118221 118227 118251 118228 118284
118236 118231 118230 118217 118232 118217 118233 118236 118235 118239 118225 118217 118249 118230 118283
118227 118228 118216 118215 118213 118213 118237 118229 118227 118230 118216 118229 118281 118235 118255
118228 118227 118232 118216 118212 118215 118231 118236 118230 118232 118216 118212 118231 118226 118250
118226 118226 118243 118214 118227 118232 118235 118243 118241 118241 118213 118226 118247 118236 118244
118215 118213 118213 118213 118212 118214 118230 118231 118229 118230 118213 118214 118246 118218 118242
118222 118224 118223 118225 118224 118214 118233 118235 118231 118237 118216 118233 118246 118244 118282
118214 118216 118213 118217 118213 118212 118221 118223 118215 118217 118234 118233 118246 118243 118231
118213 118213 118209 118216 118212 118213 118226 118230 118229 118217 118216 118209 118247 118245 118282
118214 118215 118215 118215 118213 118214 118233 118226 118236 118230 118217 118242 118274 118243 118281
118234 118216 118217 118219 118212 118216 118226 118229 118231 118226 118215 118230 118245 118240 118240
118213 118214 118212 118218 118212 118214 118224 118214 118215 118217 118218 118217 118273 118244 118281
118213 118213 118212 118214 118213 118216 118214 118215 118216 118214 118217 118207 118261 118245 118284
118214 118216 118212 118215 118219 118221 118212 118226 118212 118217 118234 118233 118245 118245 118243
118223 118226 118225 118217 118227 118213 118240 118226 118232 118226 118234 118243 118245 118246 118280
118229 118229 118230 118221 118229 118212 118238 118228 118215 118214 118231 118217 118245 118246 118241
118212 118215 118214 118215 118230 118214 118232 118227 118228 118216 118218 118212 118245 118245 118282
118217 118214 118213 118215 118225 118213 118225 118215 118216 118216 118217 118209 118245 118245 118284
118236 118233 118233 118235 118233 118238 118237 118228 118230 118214 118232 118239 118246 118247 118244
118213 118217 118230 118217 118236 118239 118234 118227 118231 118226 118231 118213 118247 118247 118243
118211 118220 118217 118211 118214 118212 118223 118215 118213 118217 118232 118217 118244 118244 118255
118213 118216 118214 118219 118215 118212 118223 118230 118231 118213 118217 118213 118247 118233 118243
118212 118216 118217 118217 118212 118214 118215 118215 118214 118215 118231 118225 118247 118246 118241

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 118245 bytes 100%
1,000 118226 bytes -19 bytes 100%
10,000 118210 bytes -16 bytes 100%
100,000 118208 bytes -2 bytes 1.16%
1,000,000 118207 bytes -1 byte 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
118306 bytes +99 bytes (+0.08%) +67 bytes
118304 bytes +97 bytes (+0.08%) +65 bytes
118274 bytes +67 bytes (+0.06%) +35 bytes
118239 bytes +32 bytes (+0.03%)
118281 bytes +74 bytes (+0.06%) +42 bytes
118303 bytes +96 bytes (+0.08%) +64 bytes
118305 bytes +98 bytes (+0.08%) +66 bytes
118252 bytes +45 bytes (+0.04%) +13 bytes
118309 bytes +102 bytes (+0.09%) +70 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 81506 bytes -36701 bytes (-31.05%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 88477 bytes -29730 bytes (-25.15%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 95019 bytes -23188 bytes (-19.62%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 101383 bytes -16824 bytes (-14.23%)
Brotli (Wikipedia) brotli brotli -q 11 103215 bytes -14992 bytes (-12.68%)
LZMA2 (Wikipedia) xz xz -9 104792 bytes -13415 bytes (-11.35%)
ZSTD (Wikipedia) zstd zstd -19 107854 bytes -10353 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 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