Choose a version:
13% The original file has 464608 bytes (453.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 62682 bytes (61.2k, 13%).

After GZIP compression these minified files vary in size:
Boot
  37044 bytes (36.2k)
CDN
cdnjs
  30558 bytes (29.8k)
CDN
cdnhttps
  30080 bytes (29.4k)
CDN
gzip -6 (default)
  20938 bytes (20.4k)
local copy
jsdelivr
  20863 bytes (20.4k)
CDN
gzip -9
  20855 bytes (20.4k)
local copy
libdeflate -12
  20229 bytes (19.8k)
local copy
7zip -mx=9 -tgzip
  20224 bytes (19.8k)
local copy
kzip -s0 -rn -b2
  20151 bytes (19.7k)
local copy
pigz -11 -n
  20102 bytes (19.6k)
local copy
Zopfli
  20072 bytes (19.6k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/lodash/lodash-4.2.0.min.js

You will automatically get the smallest lodash 4.2.0 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 791 bytes by using my lodash 4.2.0 Zopfli version instead of the best available CDN (3.94% smaller than jsdelivr, 20072 vs. 20863 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 --mls2 --bsr22 --lazy --ohh

(found April 13, 2016)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 2  --mls2
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

Verify file integrity

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

MD5:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.2.0/dist/lodash.min.js --location | md5sum
a704c26e37a7fe7d20ae1b9e2eaee6c9  -
curl --silent --compressed http://minime.stephan-brumme.com/files/lodash/lodash-4.2.0.min.zopfli.js.gz | md5sum
a704c26e37a7fe7d20ae1b9e2eaee6c9  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.2.0/dist/lodash.min.js --location | sha1sum
aa6f8c22001b2d6bbd1535a27ad3d16420e7fc8d  -
curl --silent --compressed http://minime.stephan-brumme.com/files/lodash/lodash-4.2.0.min.zopfli.js.gz | sha1sum
aa6f8c22001b2d6bbd1535a27ad3d16420e7fc8d  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
jsdelivr 20863 bytes a704c26e37a7fe7d20ae1b9e2eaee6c9 (invalid)

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Boot 37044 bytes 1a3299417271461a988bf0a83c7f6d64 < /**
< * @license
< * lodash 4.2.0 (Custom Build) lodash.com/license | Unders [...]
< * Build: `lodash -o ./dist/lodash.js`
< */
< ;(function(){function n(n,t){return n.set(t[0],t[1]),n}fun [...]
< return true}function i(n,t){for(var r=-1,e=n.length,u=-1,o [...]
< var u=n.length;for(e&&u&&(r=n[--u]);u--;)r=t(r,n[u],u,n);r [...]
< return-1}function y(n,t,r,e,u){return u(n,function(n,u,o){ [...]
< return r}function E(n,t){for(var r=n.length;r--&&-1<d(t,n[ [...]
[...]
(invalid)
cdnjs 30558 bytes 1a3299417271461a988bf0a83c7f6d64 < /**
< * @license
< * lodash 4.2.0 (Custom Build) lodash.com/license | Unders [...]
< * Build: `lodash -o ./dist/lodash.js`
< */
< ;(function(){function n(n,t){return n.set(t[0],t[1]),n}fun [...]
< return true}function i(n,t){for(var r=-1,e=n.length,u=-1,o [...]
< var u=n.length;for(e&&u&&(r=n[--u]);u--;)r=t(r,n[u],u,n);r [...]
< return-1}function y(n,t,r,e,u){return u(n,function(n,u,o){ [...]
< return r}function E(n,t){for(var r=n.length;r--&&-1<d(t,n[ [...]
[...]
(invalid)
cdnhttps 30080 bytes 1a3299417271461a988bf0a83c7f6d64 < /**
< * @license
< * lodash 4.2.0 (Custom Build) lodash.com/license | Unders [...]
< * Build: `lodash -o ./dist/lodash.js`
< */
< ;(function(){function n(n,t){return n.set(t[0],t[1]),n}fun [...]
< return true}function i(n,t){for(var r=-1,e=n.length,u=-1,o [...]
< var u=n.length;for(e&&u&&(r=n[--u]);u--;)r=t(r,n[u],u,n);r [...]
< return-1}function y(n,t,r,e,u){return u(n,function(n,u,o){ [...]
< return r}function E(n,t){for(var r=n.length;r--&&-1<d(t,n[ [...]
[...]
November 22, 2016 @ 16:35

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

Other Versions

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

4.17.5, 4.17.4, 4.17.3, 4.17.2, 4.17.1, 4.17.0, 4.16.6, 4.16.5, 4.16.4, 4.16.3, 4.16.2, 4.16.1, 4.16.0, 4.15.0, 4.14.2, 4.14.1, 4.14.0, 4.13.1, 4.13.0, 4.12.0, 4.11.2, 4.11.1, 4.11.0, 4.10.0,
4.9.0, 4.8.2, 4.8.1, 4.8.0, 4.7.0, 4.6.1, 4.6.0, 4.5.1, 4.5.0, 4.4.0, 4.3.0, 4.2.1, 4.2.0, 4.1.0, 4.0.1, 4.0.0

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

Changelog

Best Zopfli parameters so far:
Size Improvement Parameters Found
20072 bytes -2 bytes zopfli --i100000 --mls2 --bsr22 --lazy --ohh April 13, 2016 @ 12:26
20074 bytes -2 bytes zopfli --i10000 --mls2 --bsr23 --lazy --ohh April 12, 2016 @ 16:03
20076 bytes -8 bytes zopfli --i1000 --mls2 --bsr23 --lazy --ohh April 12, 2016 @ 09:52
20084 bytes zopfli --i100 --mls2 --bsr23 --lazy --ohh April 12, 2016 @ 02:31

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 @ 16:35.

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
20112 20114 20113 20116 20128 20130 20130 20121 20110 20119 20104 20106 20104 20120 20125
20082 20081 20089 20083 20089 20086 20101 20092 20088 20087 20094 20108 20108 20104 20093
20077 20079 20088 20078 20080 20084 20089 20085 20092 20092 20084 20091 20092 20092 20084
20077 20078 20078 20080 20083 20076 20078 20088 20085 20082 20090 20094 20094 20106 20094
20079 20078 20087 20083 20079 20082 20077 20086 20083 20092 20084 20094 20093 20083 20085
20079 20077 20085 20097 20077 20082 20077 20084 20090 20084 20090 20095 20093 20102 20093
20078 20080 20084 20095 20083 20082 20084 20083 20086 20085 20084 20083 20093 20089 20084
20091 20080 20086 20087 20078 20079 20089 20085 20083 20093 20087 20095 20096 20083 20091
20075 20080 20084 20084 20081 20081 20086 20086 20084 20083 20085 20079 20093 20090 20083
20077 20077 20084 20086 20079 20080 20084 20089 20084 20084 20087 20094 20093 20086 20094
20079 20080 20085 20076 20077 20075 20078 20084 20083 20084 20085 20098 20093 20088 20087
20072 20077 20085 20085 20081 20084 20078 20085 20084 20084 20093 20092 20095 20086 20087
20080 20080 20085 20085 20081 20078 20078 20085 20084 20084 20093 20092 20091 20091 20084
20075 20077 20084 20087 20082 20076 20080 20088 20084 20082 20085 20093 20093 20087 20093
20076 20077 20084 20084 20082 20081 20078 20087 20086 20086 20086 20094 20096 20087 20087
20078 20077 20086 20086 20083 20078 20087 20083 20085 20084 20092 20094 20096 20088 20082
20079 20076 20084 20085 20079 20085 20087 20085 20086 20085 20085 20094 20094 20106 20082
20077 20080 20087 20088 20082 20080 20078 20085 20086 20086 20092 20094 20092 20085 20083
20072 20077 20084 20088 20078 20080 20081 20085 20085 20085 20084 20093 20096 20089 20093
20073 20081 20083 20086 20081 20083 20082 20086 20085 20081 20085 20081 20092 20078 20083
20076 20079 20083 20083 20078 20079 20078 20086 20086 20085 20086 20093 20092 20092 20083
20082 20079 20084 20086 20085 20080 20082 20083 20086 20092 20085 20094 20091 20092 20084
20080 20081 20084 20085 20084 20080 20081 20084 20084 20082 20083 20094 20094 20082 20084

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 20084 bytes 100%
1,000 20076 bytes -8 bytes 100%
10,000 20074 bytes -2 bytes 100%
100,000 20072 bytes -2 bytes 0.87%
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
20164 bytes +92 bytes (+0.46%) +13 bytes
20224 bytes +152 bytes (+0.76%) +73 bytes
20151 bytes +79 bytes (+0.39%)
20165 bytes +93 bytes (+0.46%) +14 bytes
20151 bytes +79 bytes (+0.39%)
20162 bytes +90 bytes (+0.45%) +11 bytes
20185 bytes +113 bytes (+0.56%) +34 bytes
20205 bytes +133 bytes (+0.66%) +54 bytes
20220 bytes +148 bytes (+0.74%) +69 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 17093 bytes -2979 bytes (-14.84%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 17348 bytes -2724 bytes (-13.57%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 18389 bytes -1683 bytes (-8.38%)
Brotli (Wikipedia) brotli brotli -q 11 18966 bytes -1106 bytes (-5.51%)
LZMA2 (Wikipedia) xz xz -9 19340 bytes -732 bytes (-3.65%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 19456 bytes -616 bytes (-3.07%)
ZSTD (Wikipedia) zstd zstd -19 19962 bytes -110 bytes (-0.55%)

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