Choose a version:
14% The original file has 540512 bytes (527.8k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 73261 bytes (71.5k, 14%).

After GZIP compression these minified files vary in size:
unpkg
  28741 bytes (28.1k)
 CDN
Boot
  24631 bytes (24.1k)
 CDN
cdnjs
  24631 bytes (24.1k)
 CDN
gzip -6 (default)
  24434 bytes (23.9k)
 local copy
gzip -9
  24365 bytes (23.8k)
 local copy
7zip -mx=9 -tgzip
  23534 bytes (23.0k)
 local copy
libdeflate -12
  23522 bytes (23.0k)
 local copy
zultra
  23493 bytes (22.9k)
 local copy
kzip -s0 -rn -b3
  23459 bytes (22.9k)
 local copy
pigz -11 -n
  23409 bytes (22.9k)
 local copy
Zopfli
  23372 bytes (22.8k)
 local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/lodash/lodash-4.17.15.min.js (or via HTTPS)

You will automatically get the smallest lodash 4.17.15 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 1259 bytes by using my lodash 4.17.15 Zopfli version instead of the best available CDN (5.39% smaller than cdnjs, 23372 vs. 24631 bytes):
Download
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 --bsr40 --lazy --ohh

(found July 23, 2019)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8  --mls8
block splitting recursion 40  --bsr40
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/4.17.15/dist/lodash.min.js --location | md5sum
bc0594c54450e8ac689739b6b198067a  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.17.15.min.zopfli.js.gz | md5sum
bc0594c54450e8ac689739b6b198067a  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.17.15/dist/lodash.min.js --location | sha1sum
32f09ec3ec0950f47a35fc0d656559d5b164dacd  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.17.15.min.zopfli.js.gz | sha1sum
32f09ec3ec0950f47a35fc0d656559d5b164dacd  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
unpkg 28741 bytes bc0594c54450e8ac689739b6b198067a (invalid)
Boot 24631 bytes bc0594c54450e8ac689739b6b198067a (invalid)
cdnjs 24631 bytes bc0594c54450e8ac689739b6b198067a (invalid)

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

Other Versions

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

4.17.21, 4.17.20, 4.17.19, 4.17.18, 4.17.17, 4.17.16, 4.17.15, 4.17.14, 4.17.13, 4.17.12, 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
23372 bytes -1 byte zopfli --i1000000 --mls8 --bsr40 --lazy --ohh July 23, 2019 @ 18:06
23373 bytes -1 byte zopfli --i100000 --mls8 --bsr40 --lazy --ohh July 23, 2019 @ 14:30
23374 bytes -1 byte zopfli --i100000 --mls8 --bsr22 --lazy --ohh July 23, 2019 @ 14:14
23375 bytes -2 bytes zopfli --i10000 --mls8 --bsr22 --lazy --ohh July 23, 2019 @ 11:16
23377 bytes -5 bytes zopfli --i1000 --mls8 --bsr16 --lazy --ohh July 23, 2019 @ 10:54
23382 bytes -3 bytes zopfli --i1000 --mls8 --bsr22 --lazy --ohh July 23, 2019 @ 10:54
23385 bytes -1 byte zopfli --i1000 --mls32768 --bsr25 --lazy --ohh July 23, 2019 @ 10:54
23386 bytes -1 byte zopfli --i1000 --mls32768 --bsr9 --lazy --ohh July 23, 2019 @ 10:53
23387 bytes – zopfli --i100 --mls8 --bsr40 --lazy --ohh July 23, 2019 @ 10:38

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 @ 12:54.

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
2 23426 23427 23416 23417 23417 23418 23417 23416 23417 23474 23427 23431 23411 23430 23417
4 23407 23407 23416 23409 23409 23408 23413 23409 23420 23407 23397 23408 23404 23400 23410
6 23384 23386 23384 23401 23385 23395 23389 23397 23403 23384 23450 23408 23405 23384 23401
7 23386 23386 23385 23392 23386 23395 23388 23399 23402 23397 23433 23400 23406 23387 23406
8 23404 23386 23387 23389 23390 23396 23389 23385 23385 23438 23401 23409 23406 23383 23383
9 23387 23387 23383 23393 23385 23396 23388 23385 23424 23385 23397 23447 23404 23385 23384
10 23389 23390 23393 23384 23386 23387 23387 23388 23388 23383 23436 23403 23406 23384 23383
11 23401 23401 23401 23402 23406 23386 23388 23414 23408 23396 23402 23385 23403 23403 23411
12 23384 23386 23393 23385 23385 23385 23389 23395 23384 23384 23434 23402 23403 23402 23384
13 23405 23396 23397 23400 23386 23385 23396 23400 23404 23403 23396 23408 23404 23385 23407
14 23387 23387 23386 23385 23388 23394 23386 23385 23406 23402 23395 23405 23401 23387 23402
15 23393 23392 23388 23387 23386 23386 23386 23385 23402 23395 23396 23405 23403 23386 23408
16 23405 23403 23375 23404 23385 23386 23388 23388 23386 23385 23434 23445 23403 23384 23385
17 23386 23384 23387 23384 23385 23387 23386 23400 23403 23401 23384 23405 23418 23386 23385
18 23387 23386 23387 23400 23385 23395 23391 23399 23408 23396 23403 23406 23403 23386 23384
19 23387 23384 23385 23387 23389 23386 23400 23400 23404 23384 23437 23413 23405 23385 23384
20 23390 23384 23387 23398 23388 23387 23388 23402 23402 23438 23403 23449 23403 23385 23385
21 23387 23384 23392 23399 23386 23398 23386 23404 23403 23400 23385 23403 23403 23386 23386
22 23389 23384 23374 23401 23388 23385 23384 23384 23385 23399 23436 23406 23405 23419 23385
23 23386 23385 23387 23390 23388 23397 23389 23384 23384 23400 23386 23401 23404 23385 23383
25 23386 23386 23392 23390 23402 23386 23391 23399 23385 23402 23401 23405 23403 23385 23384
30 23386 23389 23387 23387 23386 23386 23386 23385 23384 23383 23402 23400 23403 23419 23383
40 23405 23387 23372 23399 23387 23395 23387 23386 23387 23403 23385 23396 23406 23384 23384

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 23387 bytes – 100%
1,000 23377 bytes -10 bytes 100%
10,000 23375 bytes -2 bytes 100%
100,000 23373 bytes -2 bytes 0.87%
1,000,000 23372 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
(any) 23480 bytes +108 bytes (+0.46%) +21 bytes
1 23627 bytes +255 bytes (+1.09%) +168 bytes
2 23506 bytes +134 bytes (+0.57%) +47 bytes
3 23459 bytes +87 bytes (+0.37%) –
4 23476 bytes +104 bytes (+0.44%) +17 bytes
5 23480 bytes +108 bytes (+0.46%) +21 bytes
6 23476 bytes +104 bytes (+0.44%) +17 bytes
7 23497 bytes +125 bytes (+0.53%) +38 bytes
8 23512 bytes +140 bytes (+0.60%) +53 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 19623 bytes -3749 bytes (-16.04%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 20262 bytes -3110 bytes (-13.31%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 21078 bytes -2294 bytes (-9.82%)
Brotli (Wikipedia) brotli brotli -q 11 21809 bytes -1563 bytes (-6.69%)
LZMA2 (Wikipedia) xz xz -9 22340 bytes -1032 bytes (-4.42%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 22607 bytes -765 bytes (-3.27%)
Zstandard (Wikipedia) zstd zstd -19 23100 bytes -272 bytes (-1.16%)

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):
Load and Parse Data


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 2024.
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

All trademarks are property of their respective owners. You know, the boring legal stuff.