Choose a version:
13% The original file has 515215 bytes (503.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 67891 bytes (66.3k, 13%).

After GZIP compression these minified files vary in size:
Boot
  26687 bytes (26.1k)
CDN
cdnjs
  23602 bytes (23.0k)
CDN
cdnhttps
  23368 bytes (22.8k)
CDN
unpkg
  22500 bytes (22.0k)
CDN
gzip -6 (default)
  22484 bytes (22.0k)
local copy
gzip -9
  22417 bytes (21.9k)
local copy
jsdelivr
  22416 bytes (21.9k)
CDN
libdeflate -12
  21732 bytes (21.2k)
local copy
7zip -mx=9 -tgzip
  21674 bytes (21.2k)
local copy
kzip -s0 -rn -b4
  21661 bytes (21.2k)
local copy
pigz -11 -n
  21639 bytes (21.1k)
local copy
Zopfli
  21590 bytes (21.1k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/lodash/lodash-4.13.0.min.js (or via HTTPS)

You will automatically get the smallest lodash 4.13.0 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 826 bytes by using my lodash 4.13.0 Zopfli version instead of the best available CDN (3.83% smaller than jsdelivr, 21590 vs. 22416 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 --i1000000 --mb8 --mls8 --bsr23 --lazy --ohh

(found May 24, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8  --mls8
block splitting recursion 23  --bsr23
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/4.13.0/dist/lodash.min.js --location | md5sum
f7a498e67c544d09479073f42f2add1e  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.13.0.min.zopfli.js.gz | md5sum
f7a498e67c544d09479073f42f2add1e  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.13.0/dist/lodash.min.js --location | sha1sum
a70a2338334efd81448d6f716dc81d5b1eb57891  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.13.0.min.zopfli.js.gz | sha1sum
a70a2338334efd81448d6f716dc81d5b1eb57891  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
unpkg 22500 bytes f7a498e67c544d09479073f42f2add1e July 13, 2016 @ 13:56
jsdelivr 22416 bytes f7a498e67c544d09479073f42f2add1e (invalid)

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Boot 26687 bytes e73503846f8eaf8c54f5c58f669a041e < /**
< * @license
< * lodash lodash.com/license | Underscore.js 1.8.3 undersc [...]
< */
< ;(function(){function t(t,n){return t.set(n[0],n[1]),t}fun [...]
< return t}function i(t,n){for(var r=-1,e=t?t.length:0;++r<e [...]
< var u=-1,o=t?t.length:0;for(e&&o&&(r=t[++u]);++u<o;)r=n(r, [...]
< return-1}function y(t,n,r,e){--r;for(var u=t.length;++r<u; [...]
< })}function O(t){return function(n){return t(n)}}function [...]
< }function C(t){var n=false;if(null!=t&&typeof t.toString!= [...]
[...]
(invalid)
cdnjs 23602 bytes e73503846f8eaf8c54f5c58f669a041e < /**
< * @license
< * lodash lodash.com/license | Underscore.js 1.8.3 undersc [...]
< */
< ;(function(){function t(t,n){return t.set(n[0],n[1]),t}fun [...]
< return t}function i(t,n){for(var r=-1,e=t?t.length:0;++r<e [...]
< var u=-1,o=t?t.length:0;for(e&&o&&(r=t[++u]);++u<o;)r=n(r, [...]
< return-1}function y(t,n,r,e){--r;for(var u=t.length;++r<u; [...]
< })}function O(t){return function(n){return t(n)}}function [...]
< }function C(t){var n=false;if(null!=t&&typeof t.toString!= [...]
[...]
(invalid)
cdnhttps 23368 bytes e73503846f8eaf8c54f5c58f669a041e < /**
< * @license
< * lodash lodash.com/license | Underscore.js 1.8.3 undersc [...]
< */
< ;(function(){function t(t,n){return t.set(n[0],n[1]),t}fun [...]
< return t}function i(t,n){for(var r=-1,e=t?t.length:0;++r<e [...]
< var u=-1,o=t?t.length:0;for(e&&o&&(r=t[++u]);++u<o;)r=n(r, [...]
< return-1}function y(t,n,r,e){--r;for(var u=t.length;++r<u; [...]
< })}function O(t){return function(n){return t(n)}}function [...]
< }function C(t){var n=false;if(null!=t&&typeof t.toString!= [...]
[...]
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:

4.17.11, 4.17.10, 4.17.9, 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
21590 bytes -4 bytes zopfli --i1000000 --mls8 --bsr23 --lazy --ohh May 24, 2016 @ 06:58
21594 bytes -4 bytes zopfli --i100000 --mls8 --bsr23 --lazy --ohh May 23, 2016 @ 12:48
21598 bytes -4 bytes zopfli --i10000 --mls8 --bsr23 --lazy --ohh May 23, 2016 @ 12:16
21602 bytes -9 bytes zopfli --i1000 --mls8 --bsr23 --lazy --ohh May 23, 2016 @ 12:13
21611 bytes zopfli --i100 --mls8 --bsr23 --lazy --ohh May 23, 2016 @ 12:09

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, 100,000 or 1,000,000.
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
21624 21629 21628 21648 21646 21647 21647 21650 21646 21642 21646 21643 21636 21638 21640
21607 21610 21607 21611 21611 21611 21608 21611 21625 21616 21623 21620 21615 21624 21612
21611 21606 21621 21612 21604 21606 21607 21613 21619 21615 21611 21613 21616 21611 21620
21602 21600 21608 21606 21613 21603 21620 21628 21618 21616 21611 21624 21613 21637 21610
21612 21612 21605 21614 21612 21608 21609 21611 21613 21620 21610 21619 21617 21620 21610
21608 21603 21617 21606 21609 21607 21612 21620 21615 21616 21609 21613 21619 21620 21612
21610 21611 21604 21613 21618 21611 21616 21607 21615 21616 21615 21610 21617 21632 21614
21600 21609 21608 21605 21605 21619 21615 21615 21612 21616 21611 21616 21613 21631 21607
21609 21606 21606 21606 21615 21608 21611 21618 21619 21620 21615 21613 21609 21638 21611
21605 21602 21602 21605 21616 21613 21612 21607 21615 21616 21613 21615 21617 21605 21606
21609 21603 21606 21605 21604 21611 21613 21618 21618 21619 21609 21615 21617 21624 21612
21601 21602 21605 21606 21608 21609 21615 21606 21615 21616 21613 21619 21613 21620 21616
21607 21604 21599 21618 21618 21612 21615 21607 21618 21620 21610 21614 21612 21622 21609
21611 21605 21595 21611 21611 21608 21612 21609 21618 21617 21612 21616 21617 21620 21614
21608 21604 21599 21605 21601 21614 21620 21615 21619 21620 21615 21610 21615 21608 21609
21601 21601 21612 21611 21612 21612 21619 21606 21615 21616 21609 21616 21618 21625 21612
21608 21608 21608 21605 21606 21603 21613 21617 21619 21612 21610 21613 21607 21619 21611
21601 21599 21600 21607 21614 21601 21615 21618 21609 21616 21608 21615 21619 21606 21611
21608 21600 21607 21612 21609 21615 21615 21615 21611 21619 21609 21614 21615 21606 21609
21603 21601 21590 21607 21606 21615 21610 21607 21612 21619 21612 21612 21612 21618 21612
21602 21608 21607 21606 21617 21613 21610 21609 21612 21616 21612 21613 21609 21624 21611
21607 21602 21600 21607 21613 21614 21616 21609 21614 21615 21610 21613 21615 21609 21614
21608 21603 21599 21605 21616 21613 21611 21613 21616 21617 21614 21615 21611 21621 21611

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 21611 bytes 100%
1,000 21601 bytes -10 bytes 100%
10,000 21596 bytes -5 bytes 100%
100,000 21594 bytes -2 bytes 0.58%
1,000,000 21590 bytes -4 bytes 0.29%
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
21674 bytes +84 bytes (+0.39%) +13 bytes
21723 bytes +133 bytes (+0.62%) +62 bytes
21664 bytes +74 bytes (+0.34%) +3 bytes
21674 bytes +84 bytes (+0.39%) +13 bytes
21661 bytes +71 bytes (+0.33%)
21677 bytes +87 bytes (+0.40%) +16 bytes
21701 bytes +111 bytes (+0.51%) +40 bytes
21723 bytes +133 bytes (+0.62%) +62 bytes
21748 bytes +158 bytes (+0.73%) +87 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
ZPAQ (Wikipedia) zpaq zpaq -method 69 18251 bytes -3339 bytes (-15.47%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 18567 bytes -3023 bytes (-14.00%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 18939 bytes -2651 bytes (-12.28%)
Brotli (Wikipedia) brotli brotli -q 11 20265 bytes -1325 bytes (-6.14%)
LZMA2 (Wikipedia) xz xz -9 20768 bytes -822 bytes (-3.81%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 20871 bytes -719 bytes (-3.33%)
Zstandard (Wikipedia) zstd zstd -19 21439 bytes -151 bytes (-0.70%)

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