Choose a version:
14% The original file has 539065 bytes (526.4k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 72797 bytes (71.1k, 14%).

After GZIP compression these minified files vary in size:
Boot
  28735 bytes (28.1k)
CDN
cdnjs
  25616 bytes (25.0k)
CDN
cdnhttps
  25392 bytes (24.8k)
CDN
unpkg
  24301 bytes (23.7k)
CDN
gzip -6 (default)
  24269 bytes (23.7k)
local copy
jsdelivr
  24207 bytes (23.6k)
CDN
gzip -9
  24201 bytes (23.6k)
local copy
7zip -mx=9 -tgzip
  23381 bytes (22.8k)
local copy
libdeflate -12
  23369 bytes (22.8k)
local copy
kzip -s0 -rn -b3
  23292 bytes (22.7k)
local copy
pigz -11 -n
  23261 bytes (22.7k)
local copy
Zopfli
  23221 bytes (22.7k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/lodash/lodash-4.17.1.min.js (or via HTTPS)

You will automatically get the smallest lodash 4.17.1 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

Save 986 bytes by using my lodash 4.17.1 Zopfli version instead of the best available CDN (4.25% smaller than jsdelivr, 23221 vs. 24207 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 --bsr11 --lazy --ohh

(found November 15, 2016)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8  --mls8
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

Verify file integrity

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

MD5:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.17.1/dist/lodash.min.js --location | md5sum
c72f5b6f69bdb51d3972f45e1d2691be  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.17.1.min.zopfli.js.gz | md5sum
c72f5b6f69bdb51d3972f45e1d2691be  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.17.1/dist/lodash.min.js --location | sha1sum
ad4f3b51ea2e260cadbcefd1f8ddcc42116497e6  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.17.1.min.zopfli.js.gz | sha1sum
ad4f3b51ea2e260cadbcefd1f8ddcc42116497e6  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
unpkg 24301 bytes c72f5b6f69bdb51d3972f45e1d2691be November 15, 2016 @ 10:29
jsdelivr 24207 bytes c72f5b6f69bdb51d3972f45e1d2691be (invalid)

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Boot 28735 bytes ff048853de9f5b9e7ffe88dd8a07fc59 < /**
< * @license
< * Lodash lodash.com/license | Underscore.js 1.8.3 undersc [...]
< */
< ;(function(){function n(n,t){return n.set(t[0],t[1]),n}fun [...]
< return n}function o(n,t){for(var r=-1,e=null==n?0:n.length [...]
< return n}function h(n,t,r,e){var u=-1,i=null==n?0:n.length [...]
< --r;for(var e=n.length;++r<e;)if(n[r]===t){n=r;break n}n=- [...]
< return n}function k(n,t){for(var r,e=-1,u=n.length;++e<u;) [...]
< return"\\"+Tn[n]}function L(n){var t=-1,r=Array(n.size);re [...]
[...]
November 16, 2016 @ 08:25
cdnjs 25616 bytes ff048853de9f5b9e7ffe88dd8a07fc59 < /**
< * @license
< * Lodash lodash.com/license | Underscore.js 1.8.3 undersc [...]
< */
< ;(function(){function n(n,t){return n.set(t[0],t[1]),n}fun [...]
< return n}function o(n,t){for(var r=-1,e=null==n?0:n.length [...]
< return n}function h(n,t,r,e){var u=-1,i=null==n?0:n.length [...]
< --r;for(var e=n.length;++r<e;)if(n[r]===t){n=r;break n}n=- [...]
< return n}function k(n,t){for(var r,e=-1,u=n.length;++e<u;) [...]
< return"\\"+Tn[n]}function L(n){var t=-1,r=Array(n.size);re [...]
[...]
(invalid)
cdnhttps 25392 bytes ff048853de9f5b9e7ffe88dd8a07fc59 < /**
< * @license
< * Lodash lodash.com/license | Underscore.js 1.8.3 undersc [...]
< */
< ;(function(){function n(n,t){return n.set(t[0],t[1]),n}fun [...]
< return n}function o(n,t){for(var r=-1,e=null==n?0:n.length [...]
< return n}function h(n,t,r,e){var u=-1,i=null==n?0:n.length [...]
< --r;for(var e=n.length;++r<e;)if(n[r]===t){n=r;break n}n=- [...]
< return n}function k(n,t){for(var r,e=-1,u=n.length;++e<u;) [...]
< return"\\"+Tn[n]}function L(n){var t=-1,r=Array(n.size);re [...]
[...]
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
23221 bytes -1 byte zopfli --i1000000 --mls8 --bsr11 --lazy --ohh November 15, 2016 @ 17:56
23222 bytes -1 byte zopfli --i100000 --mls8 --bsr11 --lazy --ohh November 15, 2016 @ 11:47
23223 bytes -4 bytes zopfli --i10000 --mls8 --bsr11 --lazy --ohh November 15, 2016 @ 10:57
23227 bytes -2 bytes zopfli --i1000 --mls8 --bsr11 --lazy --ohh November 15, 2016 @ 10:35
23229 bytes -3 bytes zopfli --i1000 --mls8192 --bsr10 --lazy --ohh November 15, 2016 @ 10:34
23232 bytes zopfli --i100 --mls8192 --bsr10 --lazy --ohh November 15, 2016 @ 10:33

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

Most recent activity on January 25, 2017 @ 15:29.

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
23288 23286 23278 23281 23268 23268 23265 23268 23268 23270 23275 23266 23272 23288 23276
23247 23260 23261 23292 23267 23244 23268 23247 23248 23250 23247 23255 23248 23263 23254
23238 23245 23245 23246 23239 23239 23239 23235 23234 23234 23254 23240 23239 23235 23254
23235 23236 23235 23242 23270 23236 23244 23244 23255 23241 23240 23235 23255 23245 23233
23236 23223 23236 23235 23243 23248 23238 23246 23245 23251 23227 23239 23240 23248 23245
23236 23235 23237 23233 23254 23252 23253 23251 23243 23227 23240 23259 23254 23248 23248
23236 23237 23237 23243 23242 23240 23244 23243 23244 23246 23226 23239 23226 23233 23234
23245 23226 23221 23242 23248 23236 23256 23241 23238 23223 23235 23256 23247 23246 23246
23235 23226 23234 23234 23264 23240 23237 23236 23238 23236 23235 23232 23243 23248 23235
23233 23246 23238 23241 23245 23246 23238 23254 23244 23248 23235 23229 23234 23252 23248
23238 23228 23237 23235 23239 23239 23234 23236 23239 23224 23235 23237 23255 23246 23246
23236 23227 23234 23241 23244 23235 23245 23247 23244 23246 23226 23237 23244 23248 23234
23244 23235 23238 23234 23254 23235 23231 23244 23233 23230 23226 23241 23245 23252 23245
23236 23224 23236 23235 23242 23236 23238 23241 23238 23226 23240 23228 23246 23247 23233
23243 23234 23236 23235 23241 23236 23236 23246 23245 23230 23239 23243 23235 23250 23232
23238 23226 23234 23241 23253 23237 23238 23238 23238 23223 23248 23243 23246 23252 23247
23239 23237 23236 23234 23246 23245 23239 23243 23244 23246 23226 23248 23234 23251 23242
23240 23237 23246 23245 23242 23237 23234 23238 23240 23230 23246 23236 23235 23246 23232
23239 23234 23236 23238 23239 23237 23235 23239 23240 23223 23239 23223 23246 23249 23245
23237 23223 23235 23238 23247 23236 23245 23236 23237 23229 23223 23237 23235 23251 23234
23237 23226 23234 23275 23239 23246 23233 23235 23238 23226 23235 23252 23245 23249 23247
23238 23223 23235 23235 23247 23238 23238 23245 23240 23226 23235 23251 23244 23247 23247
23237 23238 23238 23234 23247 23246 23239 23237 23239 23227 23239 23246 23246 23250 23248

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 23232 bytes 100%
1,000 23227 bytes -5 bytes 100%
10,000 23223 bytes -4 bytes 100%
100,000 23222 bytes -1 byte 3.19%
1,000,000 23221 bytes -1 byte 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
23319 bytes +98 bytes (+0.42%) +27 bytes
23475 bytes +254 bytes (+1.09%) +183 bytes
23353 bytes +132 bytes (+0.57%) +61 bytes
23292 bytes +71 bytes (+0.31%)
23310 bytes +89 bytes (+0.38%) +18 bytes
23319 bytes +98 bytes (+0.42%) +27 bytes
23310 bytes +89 bytes (+0.38%) +18 bytes
23331 bytes +110 bytes (+0.47%) +39 bytes
23358 bytes +137 bytes (+0.59%) +66 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 19493 bytes -3728 bytes (-16.05%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 20139 bytes -3082 bytes (-13.27%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 20947 bytes -2274 bytes (-9.79%)
Brotli (Wikipedia) brotli brotli -q 11 21652 bytes -1569 bytes (-6.76%)
LZMA2 (Wikipedia) xz xz -9 22216 bytes -1005 bytes (-4.33%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 22523 bytes -698 bytes (-3.01%)
Zstandard (Wikipedia) zstd zstd -19 23082 bytes -139 bytes (-0.60%)

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