Choose a version:
30% The original file has 83809 bytes (81.8k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 25038 bytes (24.5k, 30%).

After GZIP compression these minified files vary in size:
gzip -6 (default)
  8924 bytes (8.7k)
local copy
gzip -9
  8907 bytes (8.7k)
local copy
libdeflate -12
  8703 bytes (8.5k)
local copy
7zip -mx=9 -tgzip
  8699 bytes (8.5k)
local copy
kzip -s0 -rn -b0
  8695 bytes (8.5k)
local copy
pigz -11 -n
  8681 bytes (8.5k)
local copy
Zopfli
  8670 bytes (8.5k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/knockout/knockout-1.1.1.min.js (or via HTTPS)

You will automatically get the smallest Knockout 1.1.1 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

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 --mls16 --bsr12 --lazy --ohh

(found December 18, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 16  --mls16
block splitting recursion 12  --bsr12
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-1.1.1.js --location | md5sum
1d21b44d4120fca820ea89c8a021d0d0  -
curl --silent --compressed https://minime.stephan-brumme.com/files/knockout/knockout-1.1.1.min.zopfli.js.gz | md5sum
1d21b44d4120fca820ea89c8a021d0d0  -

SHA1:
curl --silent --compressed http://knockoutjs.com/downloads/knockout-1.1.1.js --location | sha1sum
a54d185ef0e5c9399c7325bfc0c440d3ca9e7bc6  -
curl --silent --compressed https://minime.stephan-brumme.com/files/knockout/knockout-1.1.1.min.zopfli.js.gz | sha1sum
a54d185ef0e5c9399c7325bfc0c440d3ca9e7bc6  -

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
8670 bytes -1 byte zopfli --i100000 --mls16 --bsr12 --lazy --ohh December 18, 2015 @ 23:31
8671 bytes -1 byte zopfli --i10000 --mls2048 --bsr22 --lazy --ohh December 18, 2015 @ 01:11
8672 bytes -1 byte zopfli --i1000 --mls32768 --bsr4 --lazy --ohh September 11, 2015 @ 18:05
8673 bytes -1 byte zopfli --i1000 --mls2048 --bsr14 --lazy --ohh September 10, 2015 @ 12:02
8674 bytes -1 byte zopfli --i1000 --mls512 --bsr16 --lazy --ohh September 10, 2015 @ 12:01
8675 bytes -1 byte zopfli --i1000 --mls512 --bsr10 --lazy --ohh September 10, 2015 @ 12:01
8676 bytes zopfli --i100 --mls2048 --bsr11 --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 @ 14:32.

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
8680 8679 8680 8680 8680 8680 8679 8678 8677 8678 8677 8677 8680 8673 8674
8673 8674 8675 8674 8673 8675 8674 8674 8680 8685 8674 8673 8673 8673 8670
8686 8686 8686 8685 8685 8675 8673 8675 8686 8671 8674 8673 8674 8673 8673
8673 8674 8673 8674 8674 8674 8673 8674 8685 8674 8674 8674 8676 8673 8673
8673 8674 8673 8674 8673 8674 8673 8685 8678 8686 8674 8672 8674 8674 8674
8672 8674 8673 8677 8677 8674 8673 8674 8686 8673 8673 8674 8673 8673 8673
8673 8673 8673 8673 8673 8674 8673 8674 8674 8674 8674 8674 8673 8673 8673
8673 8684 8673 8673 8673 8674 8673 8674 8685 8674 8673 8674 8673 8673 8673
8673 8674 8673 8670 8673 8674 8674 8674 8680 8673 8675 8684 8673 8674 8673
8673 8677 8673 8672 8674 8673 8673 8674 8674 8674 8673 8674 8674 8673 8673
8673 8674 8674 8673 8674 8674 8673 8674 8674 8678 8673 8674 8673 8673 8673
8681 8675 8672 8673 8674 8674 8686 8687 8685 8687 8673 8672 8673 8673 8672
8673 8675 8673 8673 8675 8674 8674 8674 8673 8678 8674 8673 8674 8673 8673
8675 8674 8673 8672 8673 8674 8674 8686 8674 8686 8673 8673 8674 8673 8673
8673 8675 8679 8673 8674 8674 8672 8685 8675 8686 8673 8686 8673 8673 8673
8673 8677 8673 8673 8674 8673 8674 8674 8679 8674 8673 8674 8673 8673 8673
8674 8685 8685 8685 8674 8674 8672 8672 8679 8671 8673 8674 8673 8673 8673
8673 8674 8673 8673 8674 8674 8674 8674 8679 8678 8673 8674 8674 8673 8673
8673 8675 8674 8674 8674 8674 8674 8674 8680 8674 8671 8674 8673 8673 8673
8673 8685 8678 8673 8672 8672 8672 8672 8686 8673 8675 8674 8674 8673 8673
8672 8674 8673 8674 8673 8674 8674 8674 8680 8678 8673 8677 8673 8673 8673
8673 8675 8673 8676 8673 8674 8673 8675 8679 8674 8673 8674 8673 8673 8673
8673 8674 8674 8673 8675 8674 8675 8674 8685 8674 8673 8674 8673 8673 8673

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 8675 bytes 100%
1,000 8672 bytes -3 bytes 100%
10,000 8671 bytes -1 byte 100%
100,000 8670 bytes -1 byte 5.80%
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
8695 bytes +25 bytes (+0.29%)
8696 bytes +26 bytes (+0.30%) +1 byte
8719 bytes +49 bytes (+0.57%) +24 bytes
8749 bytes +79 bytes (+0.91%) +54 bytes
8760 bytes +90 bytes (+1.04%) +65 bytes
8793 bytes +123 bytes (+1.42%) +98 bytes
8820 bytes +150 bytes (+1.73%) +125 bytes
8846 bytes +176 bytes (+2.03%) +151 bytes
8885 bytes +215 bytes (+2.48%) +190 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
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 7588 bytes -1082 bytes (-12.48%)
Brotli (Wikipedia) brotli brotli -q 11 7814 bytes -856 bytes (-9.87%)
ZPAQ (Wikipedia) zpaq zpaq -method 69 8247 bytes -423 bytes (-4.88%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 8330 bytes -340 bytes (-3.92%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 8596 bytes -74 bytes (-0.85%)
LZMA2 (Wikipedia) xz xz -9 8640 bytes -30 bytes (-0.35%)
Zstandard (Wikipedia) zstd zstd -19 8695 bytes +25 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 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