Currently best Zopfli settings

Save 958 bytes by using my Vue 1.0.26 Zopfli version instead of the best available CDN (3.75% smaller than unpkg, 25571 vs. 26529 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 --bsr11 --lazy --ohh

(found April 10, 2017)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	2048	--mls2048
block splitting recursion	11	--bsr11
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 1 more byte (25570 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://raw.githubusercontent.com/vuejs/vue/vue-1.0.26.min.js --location | md5sum
a43164fe16c570cc03ed69af981547d3  -
curl --silent --compressed https://minime.stephan-brumme.com/files/vue/vue-1.0.26.min.zopfli.js.gz | md5sum
a43164fe16c570cc03ed69af981547d3  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/vuejs/vue/vue-1.0.26.min.js --location | sha1sum
4d1cbbf0e19c02c02a23614a882ecf149e76f79f  -
curl --silent --compressed https://minime.stephan-brumme.com/files/vue/vue-1.0.26.min.zopfli.js.gz | sha1sum
4d1cbbf0e19c02c02a23614a882ecf149e76f79f  -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	31066 bytes	a43164fe16c570cc03ed69af981547d3	(invalid)
cdnjs	26836 bytes	a43164fe16c570cc03ed69af981547d3	(invalid)
jsdelivr	26595 bytes	a43164fe16c570cc03ed69af981547d3	(invalid)
unpkg	26529 bytes	a43164fe16c570cc03ed69af981547d3	April 6, 2017 @ 17:24

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

Other Versions

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

2.6.14, 2.6.13, 2.6.12, 2.6.11, 2.6.10, 2.6.9, 2.6.8, 2.6.7, 2.6.6, 2.6.5, 2.6.4, 2.6.3, 2.6.2, 2.6.1, 2.6.0, 2.5.22, 2.5.21, 2.5.20, 2.5.19, 2.5.18, 2.5.17, 2.5.16, 2.5.15, 2.5.14, 2.5.13, 2.5.12, 2.5.11, 2.5.10, 2.5.9, 2.5.8, 2.5.7, 2.5.6, 2.5.5, 2.5.4, 2.5.3, 2.5.2, 2.5.1, 2.5.0, 2.4.4, 2.4.3, 2.4.2, 2.4.1, 2.4.0, 2.3.4, 2.3.3, 2.3.2, 2.3.1, 2.3.0, 2.2.6, 2.2.5, 2.2.4, 2.2.3, 2.2.2, 2.2.1, 2.2.0, 2.1.10, 2.1.9, 2.1.8, 2.1.7, 2.1.6, 2.1.5, 2.1.4, 2.1.3, 2.1.2, 2.1.1, 2.1.0, 2.0.8, 2.0.7, 2.0.6, 2.0.5, 2.0.4, 2.0.3, 2.0.2, 2.0.1, 2.0.0,
1.0.28, 1.0.27, 1.0.26, 1.0.25, 1.0.24, 1.0.23, 1.0.22, 1.0.21, 1.0.20, 1.0.19, 1.0.18, 1.0.17, 1.0.16, 1.0.15, 1.0.14, 1.0.13, 1.0.12, 1.0.11, 1.0.10, 1.0.9,
0.10.6, 0.10.5, 0.10.4, 0.10.3, 0.10.2, 0.10.1, 0.10.0,
0.9.3, 0.9.2, 0.9.1, 0.9.0

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

Changelog

Best Zopfli parameters so far:

Size	Improvement	Parameters	Found
25571 bytes	-2 bytes	zopfli --i100000 --mls2048 --bsr11 --lazy --ohh	April 10, 2017 @ 13:31
25573 bytes	-1 byte	zopfli --i10000 --mls2048 --bsr11 --lazy --ohh	April 7, 2017 @ 02:09
25574 bytes	-2 bytes	zopfli --i10000 --mls2048 --bsr15 --lazy --ohh	April 7, 2017 @ 02:03
25576 bytes	-1 byte	zopfli --i10000 --mls64 --bsr14 --lazy --ohh	April 7, 2017 @ 01:56
25577 bytes	-2 bytes	zopfli --i1000 --mls2048 --bsr19 --lazy --ohh	April 6, 2017 @ 18:58
25579 bytes	-10 bytes	zopfli --i1000 --mls256 --bsr25 --lazy --ohh	April 6, 2017 @ 18:57
25589 bytes	–	zopfli --i100 --mls8192 --bsr18 --lazy --ohh	April 6, 2017 @ 18:04

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

Most recent activity on July 20, 2020 @ 12:47.

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
2	25602	25601	25575	25583	25579	25581	25582	25577	25575	25582	25576	25586	25581	25599	25599
4	25598	25598	25597	25598	25596	25598	25595	25576	25590	25589	25582	25584	25577	25597	25600
6	25598	25594	25590	25596	25592	25593	25596	25596	25593	25596	25578	25590	25595	25592	25597
7	25595	25594	25594	25596	25594	25594	25596	25592	25591	25582	25590	25584	25596	25593	25596
8	25594	25601	25592	25594	25594	25594	25594	25578	25576	25584	25587	25583	25591	25598	25597
9	25594	25594	25589	25595	25594	25594	25591	25586	25584	25583	25574	25584	25591	25594	25598
10	25593	25594	25592	25594	25591	25593	25596	25578	25584	25579	25576	25595	25587	25596	25598
11	25594	25594	25594	25596	25593	25595	25596	25577	25584	25583	25571	25581	25577	25599	25597
12	25594	25594	25594	25595	25594	25595	25596	25592	25585	25594	25598	25596	25591	25595	25599
13	25594	25594	25592	25594	25593	25594	25596	25582	25584	25582	25582	25583	25577	25596	25598
14	25593	25582	25594	25594	25594	25576	25575	25581	25584	25583	25585	25582	25575	25597	25598
15	25594	25594	25593	25596	25594	25595	25596	25582	25585	25583	25572	25582	25595	25593	25598
16	25594	25594	25590	25595	25594	25594	25596	25572	25598	25594	25583	25580	25589	25596	25597
17	25594	25594	25587	25596	25593	25575	25578	25577	25584	25583	25582	25580	25578	25594	25596
18	25594	25594	25593	25594	25593	25595	25596	25581	25584	25581	25574	25583	25575	25594	25598
19	25595	25595	25592	25596	25595	25595	25596	25581	25585	25593	25575	25599	25592	25596	25597
20	25594	25593	25594	25596	25593	25575	25580	25576	25583	25584	25597	25596	25591	25596	25598
21	25595	25596	25594	25594	25593	25594	25595	25581	25584	25580	25576	25581	25575	25594	25597
22	25594	25594	25589	25594	25598	25595	25593	25578	25585	25581	25574	25596	25591	25594	25598
23	25595	25596	25594	25594	25593	25596	25596	25580	25584	25581	25572	25595	25575	25598	25597
25	25594	25594	25594	25596	25593	25594	25596	25577	25583	25595	25597	25589	25591	25594	25598
30	25591	25593	25590	25595	25589	25594	25592	25582	25584	25585	25581	25583	25574	25597	25597
40	25594	25594	25592	25596	25593	25594	25596	25594	25584	25595	25575	25580	25577	25597	25597

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	25589 bytes	–	100%
1,000	25577 bytes	-12 bytes	100%
10,000	25573 bytes	-4 bytes	100%
100,000	25571 bytes	-2 bytes	3.19%
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
(any)	25649 bytes	+78 bytes (+0.31%)	+12 bytes
1	25649 bytes	+78 bytes (+0.31%)	+12 bytes
2	25637 bytes	+66 bytes (+0.26%)	–
3	25641 bytes	+70 bytes (+0.27%)	+4 bytes
4	25675 bytes	+104 bytes (+0.41%)	+38 bytes
5	25662 bytes	+91 bytes (+0.36%)	+25 bytes
6	25690 bytes	+119 bytes (+0.47%)	+53 bytes
7	25719 bytes	+148 bytes (+0.58%)	+82 bytes
8	25744 bytes	+173 bytes (+0.68%)	+107 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 - for example, your browser actually supports it !

Algorithm	Program	Parameters	Size	Compared To Best Zopfli
ZPAQ (Wikipedia)	zpaq	zpaq -method 69	21123 bytes	-4448 bytes (-17.39%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	21565 bytes	-4006 bytes (-15.67%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	22495 bytes	-3076 bytes (-12.03%)
Brotli (Wikipedia)	brotli	brotli -q 11	23886 bytes	-1685 bytes (-6.59%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	24153 bytes	-1418 bytes (-5.55%)
LZMA2 (Wikipedia)	xz	xz -9	24704 bytes	-867 bytes (-3.39%)
Zstandard (Wikipedia)	zstd	zstd -19	25245 bytes	-326 bytes (-1.27%)

Detailled Analysis