Choose a version:
53% The original file has 971467 bytes (948.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 510888 bytes (498.9k, 53%).

After GZIP compression these minified files vary in size:
Boot
  147148 bytes (143.7k)
CDN
cdnjs
  122059 bytes (119.2k)
CDN
gzip -6 (default)
  120715 bytes (117.9k)
local copy
cdnhttps
  120680 bytes (117.9k)
CDN
unpkg
  120680 bytes (117.9k)
CDN
Google
  120606 bytes (117.8k)
CDN
jsdelivr
  120548 bytes (117.7k)
CDN
gzip -9
  120260 bytes (117.4k)
local copy
libdeflate -12
  116019 bytes (113.3k)
local copy
7zip -mx=9 -tgzip
  115901 bytes (113.2k)
local copy
kzip -s0 -rn -b0
  115538 bytes (112.8k)
local copy
Zopfli
  115521 bytes (112.8k)
local copy
pigz -11 -n
  115492 bytes (112.8k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/threejs/three-r79.min.js (or via HTTPS)

You will automatically get the smallest ThreeJS 79 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 5027 bytes by using my ThreeJS 79 Zopfli version instead of the best available CDN (4.35% smaller than jsdelivr, 115521 vs. 120548 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 --mls512 --bsr21 --lazy --ohh

(found January 28, 2017)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 512  --mls512
block splitting recursion 21  --bsr21
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

Even Smaller Files Thanks To Defluff

Zopfli's output can be further optimized by the defluff tool.
In this particular case, defluff saves 5 more bytes (115516 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://raw.githubusercontent.com/mrdoob/three.js/r79/build/three.min.js --location | md5sum
717effd176c1472382d6cbe85c9f883f  -
curl --silent --compressed https://minime.stephan-brumme.com/files/threejs/three-r79.min.zopfli.js.gz | md5sum
717effd176c1472382d6cbe85c9f883f  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mrdoob/three.js/r79/build/three.min.js --location | sha1sum
c505fd07ce438e60817c74fa197139b312e8e415  -
curl --silent --compressed https://minime.stephan-brumme.com/files/threejs/three-r79.min.zopfli.js.gz | sha1sum
c505fd07ce438e60817c74fa197139b312e8e415  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 147148 bytes 717effd176c1472382d6cbe85c9f883f July 15, 2016 @ 14:08
cdnjs 122059 bytes 717effd176c1472382d6cbe85c9f883f July 15, 2016 @ 08:46
cdnhttps 120680 bytes 717effd176c1472382d6cbe85c9f883f November 22, 2016 @ 16:41
unpkg 120680 bytes 717effd176c1472382d6cbe85c9f883f July 14, 2016 @ 13:50
Google 120606 bytes 717effd176c1472382d6cbe85c9f883f December 20, 2016 @ 14:06
jsdelivr 120548 bytes 717effd176c1472382d6cbe85c9f883f February 19, 2018 @ 16:22

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

Other Versions

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

98, 97, 96, 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50

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

Changelog

Best Zopfli parameters so far:
Size Improvement Parameters Found
115521 bytes -5 bytes zopfli --i1000000 --mls512 --bsr21 --lazy --ohh January 28, 2017 @ 16:42
115526 bytes -2 bytes zopfli --i100000 --mls512 --bsr21 --lazy --ohh July 18, 2016 @ 13:14
115528 bytes -8 bytes zopfli --i100000 --mls512 --bsr9 --lazy --ohh July 14, 2016 @ 20:32
115536 bytes -2 bytes zopfli --i10000 --mls512 --bsr9 --lazy --ohh July 14, 2016 @ 13:57
115538 bytes -2 bytes zopfli --i10000 --mls512 --bsr21 --lazy --ohh July 14, 2016 @ 13:23
115540 bytes -10 bytes zopfli --i10000 --mls2048 --bsr15 --lazy --ohh July 14, 2016 @ 13:01
115550 bytes -1 byte zopfli --i1000 --mls512 --bsr21 --lazy --ohh July 14, 2016 @ 12:51
115551 bytes -8 bytes zopfli --i1000 --mls2048 --bsr15 --lazy --ohh July 14, 2016 @ 12:40
115559 bytes zopfli --i100 --mls2048 --bsr15 --lazy --ohh July 14, 2016 @ 12:03

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

Most recent activity on February 19, 2018 @ 16:22.

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
115630 115664 115744 115747 115740 115692 115643 115648 115646 115605 115647 115648 115644 115646 115754
115600 115586 115606 115607 115600 115611 115715 115611 115610 115620 115618 115604 115596 115653 115661
115601 115608 115702 115679 115669 115684 115670 115594 115721 115612 115612 115588 115569 115579 115597
115578 115588 115590 115574 115610 115582 115573 115582 115563 115617 115559 115569 115572 115564 115618
115576 115583 115552 115547 115549 115579 115581 115576 115552 115557 115567 115578 115585 115560 115634
115633 115701 115698 115698 115697 115704 115698 115601 115528 115674 115564 115579 115574 115582 115612
115701 115699 115710 115701 115710 115717 115713 115590 115676 115688 115577 115556 115670 115582 115598
115592 115595 115708 115704 115703 115713 115700 115576 115563 115574 115568 115589 115572 115561 115580
115604 115604 115586 115575 115581 115570 115575 115577 115579 115577 115580 115569 115572 115580 115617
115584 115586 115576 115578 115582 115571 115575 115571 115579 115594 115580 115589 115570 115582 115606
115588 115587 115587 115575 115544 115590 115573 115588 115577 115548 115581 115571 115588 115568 115582
115581 115565 115601 115569 115603 115598 115580 115578 115578 115593 115528 115576 115574 115593 115594
115582 115589 115603 115574 115587 115587 115615 115579 115565 115599 115575 115577 115557 115582 115621
115598 115581 115588 115573 115601 115582 115573 115583 115572 115580 115580 115569 115569 115579 115612
115597 115582 115594 115584 115585 115581 115575 115553 115571 115595 115576 115556 115569 115583 115589
115573 115579 115587 115579 115569 115576 115571 115596 115581 115582 115588 115584 115574 115568 115588
115595 115590 115579 115577 115696 115701 115696 115557 115580 115593 115577 115570 115572 115583 115618
115696 115695 115697 115699 115699 115676 115672 115549 115521 115596 115578 115569 115573 115568 115600
115698 115704 115697 115661 115715 115706 115699 115582 115690 115576 115579 115575 115576 115590 115567
115588 115589 115700 115701 115703 115699 115692 115588 115572 115578 115574 115573 115574 115581 115586
115583 115579 115579 115579 115573 115571 115570 115566 115565 115574 115589 115566 115567 115567 115572
115574 115579 115579 115574 115573 115574 115570 115559 115566 115574 115579 115565 115569 115580 115592
115577 115577 115582 115572 115572 115573 115574 115568 115571 115567 115567 115555 115566 115574 115571

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 115559 bytes 100%
1,000 115550 bytes -9 bytes 100%
10,000 115536 bytes -14 bytes 100%
100,000 115526 bytes -10 bytes 0.87%
1,000,000 115521 bytes -5 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
115538 bytes +17 bytes (+0.01%)
116156 bytes +635 bytes (+0.55%) +618 bytes
116103 bytes +582 bytes (+0.50%) +565 bytes
115990 bytes +469 bytes (+0.41%) +452 bytes
115854 bytes +333 bytes (+0.29%) +316 bytes
115772 bytes +251 bytes (+0.22%) +234 bytes
115773 bytes +252 bytes (+0.22%) +235 bytes
115655 bytes +134 bytes (+0.12%) +117 bytes
115598 bytes +77 bytes (+0.07%) +60 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 78398 bytes -37123 bytes (-32.14%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 89934 bytes -25587 bytes (-22.15%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 94773 bytes -20748 bytes (-17.96%)
Brotli (Wikipedia) brotli brotli -q 11 100354 bytes -15167 bytes (-13.13%)
LZMA2 (Wikipedia) xz xz -9 101140 bytes -14381 bytes (-12.45%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 104197 bytes -11324 bytes (-9.80%)
Zstandard (Wikipedia) zstd zstd -19 106774 bytes -8747 bytes (-7.57%)

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