Currently best Zopfli settings

Save 932 bytes by using my Vue 2.1.10 Zopfli version instead of the best available CDN (3.65% smaller than jsdelivr, 25530 vs. 26462 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 --mls1024 --bsr22 --lazy --ohh

(found April 4, 2017)

Description	Value	Parameter
iterations	100000	--i100000
maximum blocks	8	--mb8
maximum length score	1024	--mls1024
block splitting recursion	22	--bsr22
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 (25529 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-2.1.10.min.js --location | md5sum
278e59025c240af0ab1a133059b5ea22  -
curl --silent --compressed https://minime.stephan-brumme.com/files/vue/vue-2.1.10.min.zopfli.js.gz | md5sum
278e59025c240af0ab1a133059b5ea22  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/vuejs/vue/vue-2.1.10.min.js --location | sha1sum
73b7198bbd8e4a8405c168295398633c4fb44098  -
curl --silent --compressed https://minime.stephan-brumme.com/files/vue/vue-2.1.10.min.zopfli.js.gz | sha1sum
73b7198bbd8e4a8405c168295398633c4fb44098  -

All listed CDNs deliver identical contents:

CDN	Size (compressed)	MD5 (uncompressed)	Timestamp
Boot	30392 bytes	278e59025c240af0ab1a133059b5ea22	(invalid)
cdnjs	26636 bytes	278e59025c240af0ab1a133059b5ea22	(invalid)
unpkg	26503 bytes	278e59025c240af0ab1a133059b5ea22	April 4, 2017 @ 10:09
jsdelivr	26462 bytes	278e59025c240af0ab1a133059b5ea22	(invalid)

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
25530 bytes	-3 bytes	zopfli --i100000 --mls1024 --bsr22 --lazy --ohh	April 4, 2017 @ 19:47
25533 bytes	-2 bytes	zopfli --i10000 --mls1024 --bsr22 --lazy --ohh	April 4, 2017 @ 11:56
25535 bytes	-2 bytes	zopfli --i1000 --mls1024 --bsr22 --lazy --ohh	April 4, 2017 @ 10:42
25537 bytes	–	zopfli --i100 --mls1024 --bsr22 --lazy --ohh	April 4, 2017 @ 10:33

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 @ 12:50.

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	25573	25573	25575	25570	25576	25576	25572	25565	25574	25584	25586	25581	25584	25564	25582
4	25565	25568	25565	25578	25569	25568	25565	25567	25571	25582	25583	25590	25593	25557	25579
6	25565	25566	25562	25563	25575	25574	25571	25562	25572	25582	25581	25581	25562	25559	25557
7	25566	25557	25559	25565	25562	25561	25562	25566	25560	25579	25586	25582	25553	25560	25559
8	25571	25567	25561	25571	25568	25562	25575	25566	25574	25542	25581	25582	25586	25556	25557
9	25563	25563	25557	25567	25560	25564	25557	25560	25564	25535	25584	25562	25566	25560	25561
10	25562	25562	25562	25564	25563	25565	25563	25577	25561	25581	25564	25557	25564	25560	25558
11	25567	25563	25559	25569	25568	25561	25560	25561	25562	25576	25560	25561	25552	25560	25557
12	25570	25566	25564	25562	25560	25564	25559	25544	25544	25537	25563	25564	25566	25556	25561
13	25564	25566	25561	25563	25565	25566	25565	25563	25559	25541	25562	25563	25561	25555	25560
14	25562	25568	25563	25564	25559	25565	25564	25562	25566	25555	25568	25559	25560	25557	25560
15	25562	25559	25564	25569	25565	25566	25561	25562	25561	25556	25564	25557	25554	25560	25559
16	25564	25569	25565	25564	25565	25565	25561	25563	25560	25563	25564	25559	25566	25557	25566
17	25562	25564	25557	25566	25563	25562	25558	25565	25559	25542	25586	25581	25565	25559	25558
18	25562	25564	25557	25563	25567	25558	25558	25563	25564	25565	25581	25582	25565	25559	25558
19	25564	25558	25558	25564	25558	25560	25560	25561	25561	25541	25585	25560	25555	25558	25555
20	25558	25562	25558	25560	25567	25566	25561	25563	25561	25578	25557	25559	25552	25558	25553
21	25561	25563	25559	25564	25562	25565	25560	25559	25566	25566	25562	25560	25566	25559	25558
22	25561	25567	25559	25564	25566	25563	25563	25572	25562	25530	25563	25558	25553	25557	25559
23	25562	25564	25556	25571	25559	25562	25560	25561	25562	25568	25563	25558	25553	25559	25556
25	25561	25563	25557	25566	25562	25565	25559	25559	25551	25544	25563	25558	25562	25556	25555
30	25563	25566	25559	25568	25569	25564	25564	25562	25561	25562	25563	25558	25554	25554	25552
40	25563	25564	25560	25561	25560	25564	25564	25572	25564	25571	25566	25558	25567	25559	25553

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	25537 bytes	–	100%
1,000	25535 bytes	-2 bytes	100%
10,000	25533 bytes	-2 bytes	100%
100,000	25530 bytes	-3 bytes	2.03%
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)	25641 bytes	+111 bytes (+0.43%)	+9 bytes
1	25641 bytes	+111 bytes (+0.43%)	+9 bytes
2	25639 bytes	+109 bytes (+0.43%)	+7 bytes
3	25636 bytes	+106 bytes (+0.42%)	+4 bytes
4	25632 bytes	+102 bytes (+0.40%)	–
5	25654 bytes	+124 bytes (+0.49%)	+22 bytes
6	25689 bytes	+159 bytes (+0.62%)	+57 bytes
7	25716 bytes	+186 bytes (+0.73%)	+84 bytes
8	25714 bytes	+184 bytes (+0.72%)	+82 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	21315 bytes	-4215 bytes (-16.51%)
RAR (proprietary)	RAR	rar a -m5 -md64m -mc63:128t -mt1	21803 bytes	-3727 bytes (-14.60%)
PPMd (Wikipedia)	7zip	7za a -mx=9 -m0=ppmd	21875 bytes	-3655 bytes (-14.32%)
Brotli (Wikipedia)	brotli	brotli -q 11	23881 bytes	-1649 bytes (-6.46%)
Burrows-Wheeler transform (Wikipedia)	bzip2	bzip2 -9	24446 bytes	-1084 bytes (-4.25%)
LZMA2 (Wikipedia)	xz	xz -9	24600 bytes	-930 bytes (-3.64%)
Zstandard (Wikipedia)	zstd	zstd -19	25169 bytes	-361 bytes (-1.41%)

Detailled Analysis