Choose a version:
23% The original file has 1095788 bytes (1,070.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 254574 bytes (248.6k, 23%).

After GZIP compression these minified files vary in size:
Boot
  87066 bytes (85.0k)
CDN
Baidu
  72342 bytes (70.6k)
CDN
cdnjs
  72323 bytes (70.6k)
CDN
gzip -6 (default)
  71337 bytes (69.7k)
local copy
cdnhttps
  71260 bytes (69.6k)
CDN
gzip -9
  71020 bytes (69.4k)
local copy
7zip -mx=9 -tgzip
  68554 bytes (66.9k)
local copy
libdeflate -12
  68365 bytes (66.8k)
local copy
pigz -11 -n
  68365 bytes (66.8k)
local copy
kzip -s0 -rn -b1
  68330 bytes (66.7k)
local copy
Zopfli
  68246 bytes (66.6k)
local copy
Zopfli (defluff)
  68244 bytes (66.6k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-1.3.1.min.js (or via HTTPS)

You will automatically get the smallest Ember 1.3.1 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 3014 bytes by using my Ember 1.3.1 Zopfli version instead of the best available CDN (4.42% smaller than cdnhttps, 68246 vs. 71260 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 --mls2048 --bsr15 --lazy --ohh

(found November 21, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 2048  --mls2048
block splitting recursion 15  --bsr15
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 2 more bytes (68244 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://builds.emberjs.com/tags/v1.3.1/ember.min.js --location | md5sum
98169457ba5fc5dd8e8599bd963012aa  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-1.3.1.min.zopfli.js.gz | md5sum
98169457ba5fc5dd8e8599bd963012aa  -

SHA1:
curl --silent --compressed https://builds.emberjs.com/tags/v1.3.1/ember.min.js --location | sha1sum
4e5a5533f937fb89e907a84753d823da5d19bb9c  -
curl --silent --compressed https://minime.stephan-brumme.com/files/ember/ember-1.3.1.min.zopfli.js.gz | sha1sum
4e5a5533f937fb89e907a84753d823da5d19bb9c  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 87066 bytes 98169457ba5fc5dd8e8599bd963012aa March 19, 2015 @ 17:56
cdnjs 72323 bytes 98169457ba5fc5dd8e8599bd963012aa January 14, 2014 @ 20:15
cdnhttps 71260 bytes 98169457ba5fc5dd8e8599bd963012aa December 24, 2015 @ 07:33

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Baidu 72342 bytes 9a0c84836cbbc10e2d88d7df40188523 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:

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
68246 bytes -1 byte zopfli --i100000 --mls2048 --bsr15 --lazy --ohh November 21, 2015 @ 14:16
68247 bytes -1 byte zopfli --i100000 --mls2048 --bsr30 --lazy --ohh November 21, 2015 @ 09:39
68248 bytes -1 byte zopfli --i10000 --mls512 --bsr7 --lazy --ohh October 2, 2015 @ 12:00
68249 bytes -3 bytes zopfli --i10000 --mls1024 --bsr6 --lazy --ohh October 2, 2015 @ 11:59
68252 bytes -1 byte zopfli --i1000 --mls1024 --bsr6 --lazy --ohh October 2, 2015 @ 10:30
68253 bytes -2 bytes zopfli --i1000 --mls512 --bsr7 --lazy --ohh October 2, 2015 @ 10:00
68255 bytes -36 bytes zopfli --i1000 --mls8 --bsr2 --lazy --ohh October 2, 2015 @ 09:50
68291 bytes zopfli --i100 --mls32 --bsr2 --lazy --ohh September 30, 2015 @ 09:34

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 @ 07:31.

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
68253 68251 68253 68251 68251 68250 68252 68249 68253 68256 68255 68260 68257 68260 68250
68252 68253 68263 68252 68256 68252 68257 68250 68251 68250 68250 68250 68253 68258 68262
68256 68252 68257 68256 68255 68256 68317 68250 68247 68246 68251 68252 68252 68264 68253
68251 68253 68253 68252 68256 68256 68254 68246 68247 68246 68250 68252 68250 68263 68256
68255 68253 68253 68253 68254 68255 68250 68249 68251 68249 68253 68256 68254 68259 68252
68252 68253 68253 68253 68255 68252 68249 68260 68247 68246 68253 68252 68259 68267 68256
68252 68251 68253 68252 68253 68256 68255 68250 68249 68246 68250 68249 68250 68257 68251
68252 68254 68253 68253 68256 68256 68254 68246 68247 68249 68247 68249 68252 68262 68252
68252 68250 68255 68256 68255 68255 68254 68251 68247 68246 68250 68253 68254 68258 68252
68253 68252 68252 68256 68255 68256 68254 68250 68247 68246 68250 68252 68252 68256 68252
68250 68254 68253 68255 68254 68255 68252 68250 68249 68251 68250 68252 68252 68265 68258
68252 68253 68252 68256 68256 68256 68255 68250 68247 68252 68246 68252 68251 68258 68259
68254 68254 68256 68255 68256 68254 68254 68246 68247 68246 68250 68253 68251 68262 68256
68252 68255 68251 68256 68256 68256 68253 68251 68251 68250 68250 68253 68252 68257 68253
68252 68254 68252 68252 68255 68252 68255 68250 68250 68249 68250 68251 68256 68268 68261
68250 68252 68253 68255 68256 68254 68254 68250 68247 68249 68250 68253 68249 68264 68263
68252 68252 68251 68252 68255 68254 68253 68250 68251 68246 68250 68253 68253 68260 68252
68251 68257 68254 68256 68255 68256 68256 68250 68249 68246 68250 68249 68252 68260 68255
68250 68256 68255 68254 68255 68256 68254 68250 68247 68246 68250 68252 68251 68264 68251
68252 68257 68254 68251 68255 68251 68254 68250 68247 68246 68247 68252 68258 68262 68253
68252 68251 68252 68256 68255 68256 68253 68249 68249 68252 68247 68252 68249 68262 68251
68250 68257 68253 68255 68256 68252 68256 68247 68251 68246 68247 68251 68251 68266 68254
68252 68257 68253 68252 68255 68256 68319 68246 68249 68246 68250 68253 68249 68262 68252

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 68291 bytes 100%
1,000 68252 bytes -39 bytes 100%
10,000 68248 bytes -4 bytes 100%
100,000 68246 bytes -2 bytes 9.86%
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
68346 bytes +100 bytes (+0.15%) +16 bytes
68330 bytes +84 bytes (+0.12%)
68340 bytes +94 bytes (+0.14%) +10 bytes
68388 bytes +142 bytes (+0.21%) +58 bytes
68430 bytes +184 bytes (+0.27%) +100 bytes
68445 bytes +199 bytes (+0.29%) +115 bytes
68432 bytes +186 bytes (+0.27%) +102 bytes
68462 bytes +216 bytes (+0.32%) +132 bytes
68501 bytes +255 bytes (+0.37%) +171 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
However, support for Brotli is constantly growing - but your browser doesn't support it.
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 49591 bytes -18655 bytes (-27.33%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 52594 bytes -15652 bytes (-22.93%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 56464 bytes -11782 bytes (-17.26%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 59822 bytes -8424 bytes (-12.34%)
Brotli (Wikipedia) brotli brotli -q 11 60852 bytes -7394 bytes (-10.83%)
LZMA2 (Wikipedia) xz xz -9 62600 bytes -5646 bytes (-8.27%)
Zstandard (Wikipedia) zstd zstd -19 64253 bytes -3993 bytes (-5.85%)

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