Choose a version:
26% The original file has 1641515 bytes (1,603.0k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 432544 bytes (422.4k, 26%).

After GZIP compression these minified files vary in size:
Boot
  139735 bytes (136.5k)
CDN
cdnjs
  114671 bytes (112.0k)
CDN
gzip -6 (default)
  113061 bytes (110.4k)
local copy
gzip -9
  112689 bytes (110.0k)
local copy
cdnhttps
  112467 bytes (109.8k)
CDN
7zip -mx=9 -tgzip
  108874 bytes (106.3k)
local copy
libdeflate -12
  108749 bytes (106.2k)
local copy
pigz -11 -n
  108741 bytes (106.2k)
local copy
kzip -s0 -rn -b3
  108566 bytes (106.0k)
local copy
Zopfli
  108526 bytes (106.0k)
local copy
Zopfli (defluff)
  108524 bytes (106.0k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/ember/ember-2.6.1.min.js

You will automatically get the smallest Ember 2.6.1 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 3941 bytes by using my Ember 2.6.1 Zopfli version instead of the best available CDN (3.63% smaller than cdnhttps, 108526 vs. 112467 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 --mls64 --bsr4 --lazy --ohh

(found June 30, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 64  --mls64
block splitting recursion 4  --bsr4
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 (108524 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed http://builds.emberjs.com/tags/v2.6.1/ember.min.js --location | md5sum
dedb73a6af23f228e64bfc3dbe45d3e4  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.6.1.min.zopfli.js.gz | md5sum
dedb73a6af23f228e64bfc3dbe45d3e4  -

SHA1:
curl --silent --compressed http://builds.emberjs.com/tags/v2.6.1/ember.min.js --location | sha1sum
947dd5f0c4441bdbed3a237a692efcb0027aa3ce  -
curl --silent --compressed http://minime.stephan-brumme.com/files/ember/ember-2.6.1.min.zopfli.js.gz | sha1sum
947dd5f0c4441bdbed3a237a692efcb0027aa3ce  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 139735 bytes dedb73a6af23f228e64bfc3dbe45d3e4 June 28, 2016 @ 06:42
cdnjs 114671 bytes dedb73a6af23f228e64bfc3dbe45d3e4 June 27, 2016 @ 20:46
cdnhttps 112467 bytes dedb73a6af23f228e64bfc3dbe45d3e4 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
108526 bytes -2 bytes zopfli --i1000000 --mls64 --bsr4 --lazy --ohh June 30, 2016 @ 03:23
108528 bytes -2 bytes zopfli --i100000 --mls64 --bsr4 --lazy --ohh June 28, 2016 @ 19:37
108530 bytes -2 bytes zopfli --i100000 --mls2048 --bsr21 --lazy --ohh June 28, 2016 @ 19:36
108532 bytes -2 bytes zopfli --i100000 --mls4096 --bsr21 --lazy --ohh June 28, 2016 @ 10:40
108534 bytes -1 byte zopfli --i10000 --mls4096 --bsr20 --lazy --ohh June 27, 2016 @ 22:54
108535 bytes -3 bytes zopfli --i1000 --mls4096 --bsr21 --lazy --ohh June 27, 2016 @ 22:34
108538 bytes -2 bytes zopfli --i1000 --mls32 --bsr19 --lazy --ohh June 27, 2016 @ 22:25
108540 bytes -15 bytes zopfli --i1000 --mls16384 --bsr7 --lazy --ohh June 27, 2016 @ 22:24
108555 bytes zopfli --i100 --mls16384 --bsr7 --lazy --ohh June 27, 2016 @ 22:14

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
108597 108598 108598 108599 108598 108540 108599 108540 108541 108597 108599 108599 108598 108598 108547
108535 108535 108536 108548 108535 108526 108536 108535 108535 108537 108549 108536 108535 108533 108536
108535 108535 108535 108534 108535 108534 108536 108536 108535 108535 108544 108541 108534 108535 108535
108536 108536 108536 108535 108535 108535 108535 108535 108534 108538 108544 108535 108545 108538 108535
108535 108535 108536 108536 108535 108534 108535 108535 108536 108537 108536 108541 108538 108535 108535
108536 108535 108535 108535 108535 108535 108536 108536 108534 108536 108530 108535 108534 108535 108546
108536 108535 108535 108535 108535 108534 108536 108536 108534 108535 108536 108540 108534 108535 108546
108536 108536 108536 108535 108535 108535 108535 108535 108535 108536 108536 108536 108535 108535 108536
108535 108536 108536 108536 108535 108534 108535 108536 108534 108536 108535 108534 108538 108535 108546
108536 108535 108536 108536 108535 108535 108535 108536 108534 108536 108535 108534 108536 108534 108538
108536 108535 108536 108535 108536 108535 108536 108534 108535 108535 108539 108534 108536 108535 108546
108536 108534 108536 108535 108535 108534 108536 108536 108534 108536 108545 108540 108545 108535 108537
108535 108535 108535 108535 108534 108536 108535 108535 108535 108536 108544 108535 108534 108535 108535
108535 108536 108537 108535 108535 108536 108535 108536 108536 108536 108544 108539 108532 108535 108535
108535 108535 108536 108535 108535 108535 108535 108536 108536 108535 108536 108536 108539 108535 108535
108535 108535 108536 108536 108535 108535 108535 108535 108535 108531 108530 108535 108536 108535 108535
108535 108535 108535 108535 108535 108536 108535 108535 108535 108536 108533 108534 108535 108535 108538
108535 108535 108535 108535 108535 108535 108535 108535 108534 108536 108530 108532 108534 108535 108538
108535 108535 108535 108536 108535 108535 108535 108536 108534 108535 108536 108540 108536 108535 108535
108536 108535 108536 108535 108535 108534 108536 108536 108534 108536 108536 108536 108536 108535 108535
108536 108535 108535 108535 108535 108531 108536 108535 108535 108535 108543 108534 108536 108535 108535
108536 108535 108530 108535 108535 108536 108535 108536 108536 108536 108533 108536 108535 108535 108535
108535 108535 108536 108536 108535 108535 108535 108536 108534 108535 108530 108536 108532 108535 108546

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 108555 bytes 100%
1,000 108535 bytes -20 bytes 100%
10,000 108533 bytes -2 bytes 100%
100,000 108528 bytes -5 bytes 13.04%
1,000,000 108526 bytes -2 bytes 0.58%
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
108578 bytes +52 bytes (+0.05%) +12 bytes
108573 bytes +47 bytes (+0.04%) +7 bytes
108618 bytes +92 bytes (+0.08%) +52 bytes
108566 bytes +40 bytes (+0.04%)
108633 bytes +107 bytes (+0.10%) +67 bytes
108668 bytes +142 bytes (+0.13%) +102 bytes
108704 bytes +178 bytes (+0.16%) +138 bytes
108743 bytes +217 bytes (+0.20%) +177 bytes
108808 bytes +282 bytes (+0.26%) +242 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 74365 bytes -34161 bytes (-31.48%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 79282 bytes -29244 bytes (-26.95%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 85691 bytes -22835 bytes (-21.04%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 90346 bytes -18180 bytes (-16.75%)
Brotli (Wikipedia) brotli brotli -q 11 94436 bytes -14090 bytes (-12.98%)
LZMA2 (Wikipedia) xz xz -9 96544 bytes -11982 bytes (-11.04%)
ZSTD (Wikipedia) zstd zstd -19 99284 bytes -9242 bytes (-8.52%)

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