Choose a version:
13% The original file has 542559 bytes (529.8k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 72805 bytes (71.1k, 13%).

After GZIP compression these minified files vary in size:
unpkg
  29382 bytes (28.7k)
CDN
gzip -6 (default)
  25817 bytes (25.2k)
local copy
gzip -9
  25768 bytes (25.2k)
local copy
libdeflate -12
  24984 bytes (24.4k)
local copy
7zip -mx=9 -tgzip
  24832 bytes (24.3k)
local copy
zultra
  24788 bytes (24.2k)
local copy
pigz -11 -n
  24736 bytes (24.2k)
local copy
kzip -s0 -rn -b6
  24675 bytes (24.1k)
local copy
Zopfli
  24620 bytes (24.0k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/lodash/lodash-4.17.18.min.js (or via HTTPS)

You will automatically get the smallest lodash 4.17.18 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 4762 bytes by using my lodash 4.17.18 Zopfli version instead of the best available CDN (19.34% smaller than unpkg, 24620 vs. 29382 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 --mls8192 --bsr17 --lazy --ohh

(found July 13, 2020)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8192  --mls8192
block splitting recursion 17  --bsr17
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/4.17.18/dist/lodash.min.js --location | md5sum
fc365f725403909210bb6b64f3dfe99c  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.17.18.min.zopfli.js.gz | md5sum
fc365f725403909210bb6b64f3dfe99c  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/lodash/lodash/4.17.18/dist/lodash.min.js --location | sha1sum
71ac8bb99781b8badc7641ac6c675220dfa22d4d  -
curl --silent --compressed https://minime.stephan-brumme.com/files/lodash/lodash-4.17.18.min.zopfli.js.gz | sha1sum
71ac8bb99781b8badc7641ac6c675220dfa22d4d  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
unpkg 29382 bytes fc365f725403909210bb6b64f3dfe99c (invalid)

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

Other Versions

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

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
24620 bytes -3 bytes zopfli --i1000000 --mls8192 --bsr17 --lazy --ohh July 13, 2020 @ 17:36
24623 bytes -3 bytes zopfli --i100000 --mls8192 --bsr17 --lazy --ohh July 13, 2020 @ 11:14
24626 bytes -4 bytes zopfli --i10000 --mls8192 --bsr17 --lazy --ohh July 11, 2020 @ 11:08
24630 bytes -5 bytes zopfli --i1000 --mls8192 --bsr17 --lazy --ohh July 10, 2020 @ 18:13
24635 bytes -1 byte zopfli --i1000 --mls32 --bsr25 --lazy --ohh July 10, 2020 @ 17:21
24636 bytes zopfli --i100 --mls8192 --bsr17 --lazy --ohh July 10, 2020 @ 16:40

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 @ 12:56.

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
24749 24746 24727 24743 24740 24731 24776 24716 24720 24735 24725 24739 24744 24728 24722
24674 24653 24660 24696 24687 24677 24672 24671 24695 24687 24671 24666 24660 24653 24672
24659 24660 24718 24663 24658 24656 24653 24703 24661 24662 24660 24715 24643 24659 24702
24709 24662 24713 24708 24704 24704 24696 24701 24702 24707 24701 24703 24702 24721 24710
24706 24666 24718 24706 24721 24701 24706 24702 24702 24704 24718 24714 24683 24706 24701
24665 24682 24722 24701 24720 24707 24700 24692 24714 24707 24704 24720 24692 24692 24702
24675 24673 24725 24654 24655 24643 24697 24636 24653 24648 24638 24713 24656 24702 24704
24654 24658 24666 24648 24643 24646 24644 24642 24662 24649 24652 24647 24647 24651 24663
24651 24653 24655 24656 24641 24642 24648 24649 24656 24652 24645 24655 24643 24646 24641
24647 24705 24652 24637 24641 24640 24648 24639 24649 24649 24636 24701 24651 24635 24706
24723 24669 24716 24705 24638 24656 24697 24703 24666 24703 24699 24702 24652 24714 24701
24636 24660 24715 24632 24646 24636 24702 24652 24659 24655 24637 24645 24645 24660 24661
24644 24668 24711 24644 24639 24643 24703 24705 24705 24701 24697 24707 24694 24708 24706
24639 24650 24664 24636 24626 24647 24651 24643 24640 24654 24704 24707 24620 24657 24703
24638 24656 24656 24638 24642 24649 24654 24640 24655 24659 24645 24652 24647 24656 24662
24635 24665 24648 24645 24636 24638 24703 24636 24650 24651 24642 24644 24633 24654 24654
24638 24665 24656 24641 24648 24635 24705 24643 24658 24660 24644 24652 24647 24656 24658
24666 24653 24712 24654 24627 24699 24697 24640 24665 24660 24642 24706 24655 24652 24706
24662 24663 24711 24696 24625 24647 24703 24698 24704 24699 24655 24700 24692 24698 24713
24663 24658 24659 24650 24633 24640 24644 24643 24664 24650 24710 24652 24645 24652 24696
24638 24641 24654 24637 24628 24644 24645 24653 24665 24650 24640 24699 24646 24649 24656
24635 24658 24651 24640 24634 24642 24654 24639 24664 24711 24704 24650 24695 24703 24659
24645 24652 24662 24636 24644 24659 24640 24649 24651 24653 24635 24710 24644 24651 24656

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 24636 bytes 100%
1,000 24630 bytes -6 bytes 100%
10,000 24626 bytes -4 bytes 100%
100,000 24623 bytes -3 bytes 1.45%
1,000,000 24620 bytes -3 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
24718 bytes +98 bytes (+0.40%) +43 bytes
24974 bytes +354 bytes (+1.44%) +299 bytes
24826 bytes +206 bytes (+0.84%) +151 bytes
24769 bytes +149 bytes (+0.61%) +94 bytes
24724 bytes +104 bytes (+0.42%) +49 bytes
24711 bytes +91 bytes (+0.37%) +36 bytes
24675 bytes +55 bytes (+0.22%)
24696 bytes +76 bytes (+0.31%) +21 bytes
24711 bytes +91 bytes (+0.37%) +36 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 20755 bytes -3865 bytes (-15.70%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 21813 bytes -2807 bytes (-11.40%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 21889 bytes -2731 bytes (-11.09%)
Brotli (Wikipedia) brotli brotli -q 11 22950 bytes -1670 bytes (-6.78%)
LZMA2 (Wikipedia) xz xz -9 23392 bytes -1228 bytes (-4.99%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 24180 bytes -440 bytes (-1.79%)
Zstandard (Wikipedia) zstd zstd -19 24401 bytes -219 bytes (-0.89%)

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 2020.
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.