Choose a version:
29% The original file has 88016 bytes (86.0k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 25869 bytes (25.3k, 29%).

After GZIP compression these minified files vary in size:
gzip -6 (default)
  9263 bytes (9.0k)
local copy
gzip -9
  9244 bytes (9.0k)
local copy
libdeflate -12
  9029 bytes (8.8k)
local copy
kzip -s0 -rn -b0
  9018 bytes (8.8k)
local copy
7zip -mx=9 -tgzip
  9015 bytes (8.8k)
local copy
pigz -11 -n
  9013 bytes (8.8k)
local copy
Zopfli
  8993 bytes (8.8k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/knockout/knockout-1.1.2.min.js

You will automatically get the smallest Knockout 1.1.2 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

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 --i10000 --mb8 --mls8 --bsr4 --lazy --ohh

(found November 23, 2015)
Description Value Parameter
iterations 10000  --i10000
maximum blocks 8  --mb8
maximum length score 8  --mls8
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

Verify file integrity

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

MD5:
curl --silent --compressed http://knockoutjs.com/downloads/knockout-1.1.2.js --location | md5sum
2c7a74045debccb44ad98f24f9821358  -
curl --silent --compressed http://minime.stephan-brumme.com/files/knockout/knockout-1.1.2.min.zopfli.js.gz | md5sum
2c7a74045debccb44ad98f24f9821358  -

SHA1:
curl --silent --compressed http://knockoutjs.com/downloads/knockout-1.1.2.js --location | sha1sum
a921940279974158c3d985ff5fc5c2c86eb78c73  -
curl --silent --compressed http://minime.stephan-brumme.com/files/knockout/knockout-1.1.2.min.zopfli.js.gz | sha1sum
a921940279974158c3d985ff5fc5c2c86eb78c73  -

Other Versions

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

3.4.2, 3.4.1, 3.4.0,
3.3.0,
3.2.0,
3.1.0,
3.0.0,
2.3.0,
2.2.1, 2.2.0,
2.1.0,
2.0.0,
1.2.1, 1.2.0,
1.1.2, 1.1.1, 1.1.0

The project site contains an overview how well these versions were compressed.
Other interesting projects are AngularJS, BackboneJS, Bootstrap, D3, Dojo, Ember, jQuery, lodash, React, Socket.IO, ThreeJS, UnderscoreJS and Vue.

Changelog

Best Zopfli parameters so far:
Size Improvement Parameters Found
8993 bytes -1 byte zopfli --i10000 --mls8 --bsr4 --lazy --ohh November 23, 2015 @ 18:06
8994 bytes -1 byte zopfli --i1000 --mls16384 --bsr8 --lazy --ohh September 11, 2015 @ 18:03
8995 bytes -2 bytes zopfli --i1000 --mls16384 --bsr7 --lazy --ohh September 11, 2015 @ 17:58
8997 bytes -1 byte zopfli --i1000 --mls8192 --bsr11 --lazy --ohh September 10, 2015 @ 12:01
8998 bytes zopfli --i100 --mls8192 --bsr8 --lazy --ohh September 10, 2015 @ 11:35

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

Most recent activity on June 16, 2016 @ 14:34.

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
8997 8997 8998 8998 8998 8999 9016 9016 9016 9010 9000 9001 8998 8997 8997
8993 9006 8993 8998 9000 9000 9011 9016 9016 9009 9009 9001 9000 8998 8995
9007 8996 8999 8996 9000 8998 9003 9009 9016 9011 9002 9010 8994 8993 9008
8996 8996 9000 8998 8999 9012 9012 9012 9016 9009 9001 8996 8999 8993 8995
9003 8997 9003 9003 8998 9003 9012 9009 9016 9011 9000 9008 8996 8993 9011
8997 9003 8995 9004 8998 9004 9003 9003 9010 9004 9001 9004 9004 8997 8996
8997 8996 8999 8997 9001 8998 9011 9003 8997 9009 9001 9009 8999 8996 8996
8998 8997 9009 8997 8998 8997 9012 9009 8999 9009 8999 9004 8994 8995 9010
8998 8999 8999 8997 8999 9004 8999 9009 9008 9010 9000 9000 9004 8998 9002
8999 8998 9000 9003 8999 9003 8999 9009 9016 9011 9000 9009 8994 8998 8996
9000 8998 8999 8998 8999 9004 9012 9004 9010 9011 8999 9004 9004 8998 8993
8999 9007 9000 8998 8999 9005 9012 9009 9008 9009 8999 9010 8999 8993 8993
9012 8999 9000 8994 8999 9005 9003 9004 9010 9008 9001 9003 9003 8996 8995
8998 8997 9000 8998 8999 9003 9003 9003 8999 9005 9000 9005 8996 8998 9010
9007 9010 9000 9010 9009 9004 9004 9004 9010 9009 8998 9009 9003 8997 8996
8996 8998 8999 8998 8999 9003 8999 9000 9010 8998 8997 9009 9004 8997 8993
8998 8998 9000 8997 8998 9004 9012 9009 9011 9011 8999 9009 8996 8993 8995
8999 8998 8999 8998 9001 9004 9011 9012 9010 9009 9009 8996 9003 8998 8996
8998 8998 9000 8997 8999 9004 9000 9000 9010 8999 8999 9009 9003 8998 8995
9000 8998 9009 8998 8998 9004 9003 9009 8999 9007 8999 9004 9004 8993 8996
8998 8996 9009 8996 8998 9004 9012 9009 9010 9008 8999 8996 9003 8998 9009
8999 8996 9000 8996 9000 8998 8998 9010 9010 9010 9001 8996 9004 8996 8995
8996 8998 9009 8996 8996 9012 9012 9010 9016 9009 8997 9009 8995 8997 8995

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 8997 bytes 100%
1,000 8994 bytes -3 bytes 100%
10,000 8993 bytes -1 byte 100%
100,000 8993 bytes 7.25%
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
9018 bytes +25 bytes (+0.28%)
9018 bytes +25 bytes (+0.28%)
9041 bytes +48 bytes (+0.53%) +23 bytes
9071 bytes +78 bytes (+0.87%) +53 bytes
9084 bytes +91 bytes (+1.01%) +66 bytes
9118 bytes +125 bytes (+1.39%) +100 bytes
9143 bytes +150 bytes (+1.67%) +125 bytes
9188 bytes +195 bytes (+2.17%) +170 bytes
9212 bytes +219 bytes (+2.44%) +194 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
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 7861 bytes -1132 bytes (-12.59%)
Brotli (Wikipedia) brotli brotli -q 11 8107 bytes -886 bytes (-9.85%)
ZPAQ (Wikipedia) zpaq zpaq -method 69 8523 bytes -470 bytes (-5.23%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 8628 bytes -365 bytes (-4.06%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 8853 bytes -140 bytes (-1.56%)
LZMA2 (Wikipedia) xz xz -9 8948 bytes -45 bytes (-0.50%)
ZSTD (Wikipedia) zstd zstd -19 9019 bytes +26 bytes (+0.29%)

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