Choose a version:
47% The original file has 465073 bytes (454.2k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 218251 bytes (213.1k, 47%).

After GZIP compression these minified files vary in size:
Boot
  83879 bytes (81.9k)
CDN, direct link
cdnjs
  73952 bytes (72.2k)
CDN, direct link
gzip -6 (default)
  73373 bytes (71.7k)
local copy
gzip -9
  73092 bytes (71.4k)
local copy
libdeflate -12
  70106 bytes (68.5k)
local copy
7zip -mx=9 -tgzip
  69909 bytes (68.3k)
local copy
kzip -s0 -rn -b6
  69487 bytes (67.9k)
local copy
pigz -11 -n
  69451 bytes (67.8k)
local copy
Zopfli
  69375 bytes (67.7k)
local copy
Zopfli (defluff)
  69370 bytes (67.7k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/d3/d3-4.10.0.min.js

You will automatically get the smallest D3 4.10.0 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 4577 bytes by using my D3 4.10.0 Zopfli version instead of the best available CDN (6.60% smaller than cdnjs, 69375 vs. 73952 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 --mls2048 --bsr6 --lazy --ohh

(found July 19, 2017)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 2048  --mls2048
block splitting recursion 6  --bsr6
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 (69370 bytes).

Verify file integrity

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

MD5:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v4.10.0/d3.zip --location | md5sum
57e16c8500af785056c1f8565bc81fc8  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-4.10.0.min.zopfli.js.gz | md5sum
57e16c8500af785056c1f8565bc81fc8  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v4.10.0/d3.zip --location | sha1sum
cd77ac7ae53a30b5d15be2cc9d32d2caff818087  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-4.10.0.min.zopfli.js.gz | sha1sum
cd77ac7ae53a30b5d15be2cc9d32d2caff818087  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 83879 bytes 57e16c8500af785056c1f8565bc81fc8 July 17, 2017 @ 10:09
cdnjs 73952 bytes 57e16c8500af785056c1f8565bc81fc8 July 14, 2017 @ 23:33

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

Other Versions

Available D3 versions at minime.stephan-brumme.com:

4.10.0,
4.9.1, 4.9.0, 4.8.0, 4.7.4, 4.7.3, 4.7.2, 4.7.1, 4.7.0, 4.6.0, 4.5.0, 4.4.4, 4.4.3, 4.4.2, 4.4.1, 4.4.0, 4.3.0, 4.2.8, 4.2.7, 4.2.6, 4.2.5, 4.2.4, 4.2.3, 4.2.2, 4.2.1, 4.2.0, 4.1.1, 4.1.0, 4.0.0,
3.5.17, 3.5.16, 3.5.15, 3.5.14, 3.5.13, 3.5.12, 3.5.11, 3.5.10, 3.5.9, 3.5.8, 3.5.7, 3.5.6, 3.5.5, 3.5.4, 3.5.3, 3.5.2, 3.5.1, 3.5.0, 3.4.13, 3.4.12, 3.4.11, 3.4.10, 3.4.9, 3.4.8, 3.4.6, 3.4.5, 3.4.4, 3.4.3, 3.4.2, 3.4.1, 3.4.0, 3.3.13, 3.3.12, 3.3.11, 3.3.10, 3.3.9, 3.3.8, 3.3.7, 3.3.6, 3.3.5, 3.3.4, 3.3.3, 3.3.2, 3.3.1, 3.3.0, 3.2.8, 3.2.7, 3.2.6, 3.2.5, 3.2.4, 3.2.3, 3.2.2, 3.2.1, 3.2.0, 3.1.10, 3.1.9, 3.1.8, 3.1.7, 3.1.6, 3.1.5, 3.1.4, 3.1.3, 3.1.2, 3.1.1, 3.1.0, 3.0.8, 3.0.7, 3.0.6, 3.0.5, 3.0.4, 3.0.3, 3.0.2, 3.0.1, 3.0.0

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

Changelog

Best Zopfli parameters so far:
Size Improvement Parameters Found
69375 bytes -6 bytes zopfli --i1000000 --mls2048 --bsr6 --lazy --ohh July 19, 2017 @ 10:00
69381 bytes -6 bytes zopfli --i100000 --mls2048 --bsr6 --lazy --ohh July 18, 2017 @ 03:22
69387 bytes -7 bytes zopfli --i10000 --mls2048 --bsr6 --lazy --ohh July 17, 2017 @ 21:49
69394 bytes -16 bytes zopfli --i1000 --mls2048 --bsr6 --lazy --ohh July 17, 2017 @ 18:30
69410 bytes zopfli --i100 --mls2048 --bsr6 --lazy --ohh July 17, 2017 @ 18:03

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

Most recent activity on July 19, 2017 @ 13:01.

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
69580 69975 69556 69578 69565 69564 69498 69505 69560 69602 69645 69680 69660 69650 69629
69497 69474 69837 69835 69822 69819 69537 69502 69475 69504 69471 69454 69596 69593 69540
69466 69474 69442 69526 69441 69450 69448 69441 69420 69463 69375 69429 69450 69423 69549
69478 69533 69459 69432 69431 69431 69522 69576 69417 69438 69440 69412 69557 69463 69486
69447 69555 69421 69416 69443 69411 69432 69423 69414 69474 69442 69430 69565 69444 69482
69492 69466 69448 69468 69462 69445 69458 69453 69414 69461 69463 69591 69421 69388 69458
69456 69420 69493 69440 69468 69468 69459 69420 69429 69422 69457 69401 69570 69464 69424
69492 69482 69427 69428 69447 69438 69480 69426 69424 69424 69437 69468 69567 69469 69412
69453 69447 69417 69441 69420 69417 69418 69420 69423 69460 69403 69404 69539 69458 69423
69418 69449 69420 69440 69423 69415 69457 69421 69416 69430 69435 69408 69564 69468 69425
69463 69463 69412 69437 69454 69415 69454 69431 69450 69454 69429 69480 69542 69487 69431
69450 69431 69459 69421 69416 69406 69455 69434 69419 69437 69443 69408 69433 69422 69422
69453 69452 69423 69423 69564 69420 69448 69429 69424 69426 69417 69571 69567 69482 69427
69453 69446 69416 69459 69421 69417 69422 69443 69446 69442 69411 69406 69538 69493 69445
69454 69441 69420 69427 69420 69439 69547 69417 69416 69426 69425 69392 69571 69420 69426
69467 69459 69407 69422 69418 69425 69446 69417 69424 69461 69422 69404 69574 69571 69465
69454 69422 69437 69440 69434 69427 69545 69420 69417 69454 69424 69585 69470 69429 69417
69453 69419 69424 69442 69424 69424 69456 69394 69418 69426 69418 69393 69563 69438 69471
69420 69452 69418 69430 69432 69467 69526 69415 69419 69470 69415 69403 69566 69562 69461
69418 69415 69420 69432 69430 69417 69446 69421 69414 69428 69422 69584 69568 69417 69433
69452 69443 69423 69441 69456 69418 69445 69424 69436 69425 69436 69423 69424 69428 69440
69417 69417 69420 69433 69425 69467 69427 69416 69421 69465 69424 69400 69564 69434 69425
69455 69448 69421 69439 69453 69416 69448 69441 69415 69431 69435 69393 69530 69473 69453

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 69410 bytes 100%
1,000 69394 bytes -16 bytes 100%
10,000 69387 bytes -7 bytes 100%
100,000 69381 bytes -6 bytes 1.74%
1,000,000 69375 bytes -6 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
69625 bytes +250 bytes (+0.36%) +138 bytes
70851 bytes +1476 bytes (+2.13%) +1364 bytes
70701 bytes +1326 bytes (+1.91%) +1214 bytes
69629 bytes +254 bytes (+0.37%) +142 bytes
69629 bytes +254 bytes (+0.37%) +142 bytes
69616 bytes +241 bytes (+0.35%) +129 bytes
69487 bytes +112 bytes (+0.16%)
69507 bytes +132 bytes (+0.19%) +20 bytes
69512 bytes +137 bytes (+0.20%) +25 bytes

Non-DEFLATE Algorithms

Archivers based on completely different compression algorithms often produce superior results.
Unfortunately, browsers only support gzip compression at the moment.
Algorithm Program Parameters Size Compared To Best Zopfli
ZPAQ (Wikipedia) zpaq zpaq -method 69 54473 bytes -14902 bytes (-21.48%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 60116 bytes -9259 bytes (-13.35%)
LZMA2 (Wikipedia) xz xz -9 61420 bytes -7955 bytes (-11.47%)
Brotli (Wikipedia) brotli brotli -q 11 61465 bytes -7910 bytes (-11.40%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 62263 bytes -7112 bytes (-10.25%)
ZSTD (Wikipedia) zstd zstd -19 66749 bytes -2626 bytes (-3.79%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 67557 bytes -1818 bytes (-2.62%)

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 2017.
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