Choose a version:
48% The original file has 554713 bytes (541.7k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 267786 bytes (261.5k, 48%).

After GZIP compression these minified files vary in size:
unpkg
  101361 bytes (99.0k)
CDN
Boot
  88482 bytes (86.4k)
CDN
cdnjs
  88482 bytes (86.4k)
CDN
gzip -6 (default)
  87898 bytes (85.8k)
local copy
gzip -9
  87621 bytes (85.6k)
local copy
libdeflate -12
  84170 bytes (82.2k)
local copy
7zip -mx=9 -tgzip
  83737 bytes (81.8k)
local copy
kzip -s0 -rn -b7
  83628 bytes (81.7k)
local copy
zultra
  83474 bytes (81.5k)
local copy
pigz -11 -n
  83353 bytes (81.4k)
local copy
Zopfli
  83160 bytes (81.2k)
local copy
Zopfli (defluff)
  83159 bytes (81.2k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/d3/d3-6.2.0.min.js (or via HTTPS)

You will automatically get the smallest D3 6.2.0 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 5322 bytes by using my D3 6.2.0 Zopfli version instead of the best available CDN (6.40% smaller than cdnjs, 83160 vs. 88482 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 --bsr12 --lazy --ohh

(found September 28, 2020)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 8192  --mls8192
block splitting recursion 12  --bsr12
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 1 more byte (83159 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/v6.2.0/d3.zip --location | md5sum
c6d0c97a2d09d721fb5fba15928d9a0b  -
curl --silent --compressed https://minime.stephan-brumme.com/files/d3/d3-6.2.0.min.zopfli.js.gz | md5sum
c6d0c97a2d09d721fb5fba15928d9a0b  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v6.2.0/d3.zip --location | sha1sum
23b20ed1332ef5215af277475f5745de6f7bb2cd  -
curl --silent --compressed https://minime.stephan-brumme.com/files/d3/d3-6.2.0.min.zopfli.js.gz | sha1sum
23b20ed1332ef5215af277475f5745de6f7bb2cd  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
unpkg 101361 bytes c6d0c97a2d09d721fb5fba15928d9a0b (invalid)
Boot 88482 bytes c6d0c97a2d09d721fb5fba15928d9a0b September 23, 2020 @ 20:09
cdnjs 88482 bytes c6d0c97a2d09d721fb5fba15928d9a0b September 23, 2020 @ 20:09

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

Other Versions

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

6.2.0, 6.1.1, 6.1.0, 6.0.0,
5.16.0, 5.15.1, 5.15.0, 5.14.2, 5.14.1, 5.14.0, 5.13.1, 5.13.0, 5.12.0, 5.11.0, 5.10.1, 5.10.0,
5.9.7, 5.9.6, 5.9.5, 5.9.4, 5.9.3, 5.9.2, 5.9.1, 5.9.0, 5.8.2, 5.8.1, 5.8.0, 5.7.0, 5.6.0, 5.5.0, 5.4.0, 5.3.0, 5.2.0, 5.1.0, 5.0.1, 5.0.0,
4.13.0, 4.12.2, 4.12.1, 4.12.0, 4.11.0, 4.10.2, 4.10.1, 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
83160 bytes -2 bytes zopfli --i1000000 --mls8192 --bsr12 --lazy --ohh September 28, 2020 @ 23:18
83162 bytes -7 bytes zopfli --i100000 --mls8192 --bsr12 --lazy --ohh September 28, 2020 @ 12:57
83169 bytes -9 bytes zopfli --i10000 --mls8192 --bsr12 --lazy --ohh September 25, 2020 @ 18:46
83178 bytes -3 bytes zopfli --i1000 --mls8192 --bsr12 --lazy --ohh September 25, 2020 @ 17:12
83181 bytes -34 bytes zopfli --i1000 --mls8192 --bsr40 --lazy --ohh September 25, 2020 @ 17:11
83215 bytes zopfli --i100 --mls8192 --bsr12 --lazy --ohh September 25, 2020 @ 17:06

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

Most recent activity on September 29, 2020 @ 11:49.

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
83582 83565 83533 83539 83528 83529 83521 83537 83579 83598 83475 83463 83484 83528 83604
83770 83762 83939 83813 83491 83482 83491 83298 83473 83311 83259 83248 83239 83523 83445
83518 83449 83454 83421 83434 83460 83392 83388 83444 83494 83230 83388 83209 83224 83205
83458 83481 83476 83637 83421 83463 83368 83473 83467 83330 83343 83424 83397 83418 83372
83458 83478 83432 83428 83428 83429 83428 83421 83433 83423 83341 83237 83289 83384 83275
83563 83543 83547 83554 83369 83412 83390 83414 83430 83436 83236 83235 83467 83290 83432
83565 83590 83393 83573 83381 83394 83263 83335 83343 83337 83238 83239 83346 83304 83359
83593 83475 83455 83427 83440 83446 83432 83438 83433 83490 83267 83232 83384 83433 83434
83650 83612 83438 83430 83444 83430 83433 83443 83437 83239 83350 83256 83160 83384 83433
83588 83616 83568 83569 83395 83437 83437 83452 83434 83333 83231 83229 83187 83388 83716
83564 83590 83548 83575 83566 83413 83426 83424 83429 83496 83570 83380 83436 83700 83718
83444 83485 83438 83754 83440 83446 83570 83433 83441 83346 83281 83522 83379 83513 83524
83583 83557 83561 83457 83238 83365 83437 83437 83434 83427 83232 83376 83321 83327 83710
83614 83454 83580 83454 83554 83590 83433 83562 83433 83435 83333 83401 83605 83331 83523
83575 83553 83577 83557 83550 83455 83440 83421 83434 83338 83234 83431 83323 83326 83572
83572 83404 83397 83386 83444 83432 83428 83451 83437 83444 83431 83427 83382 83329 83375
83564 83548 83546 83560 83553 83447 83447 83450 83434 83429 83239 83384 83177 83692 83523
83587 83584 83452 83582 83545 83238 83435 83410 83333 83429 83230 83409 83268 83387 83717
83576 83536 83555 83548 83554 83431 83234 83434 83329 83333 83347 83235 83250 83338 83717
83591 83462 83568 83436 83555 83436 83438 83450 83436 83255 83229 83433 83357 83391 83451
83569 83572 83411 83443 83446 83428 83431 83384 83434 83233 83365 83369 83371 83609 83722
83571 83570 83399 83572 83552 83437 83435 83446 83428 83406 83403 83404 83420 83620 83518
83584 83576 83562 83434 83552 83482 83433 83434 83399 83439 83415 83400 83166 83715 83521

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 83215 bytes 100%
1,000 83178 bytes -37 bytes 100%
10,000 83169 bytes -9 bytes 100%
100,000 83162 bytes -7 bytes 0.87%
1,000,000 83160 bytes -2 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
83660 bytes +500 bytes (+0.60%) +32 bytes
85029 bytes +1869 bytes (+2.25%) +1401 bytes
84865 bytes +1705 bytes (+2.05%) +1237 bytes
83657 bytes +497 bytes (+0.60%) +29 bytes
83663 bytes +503 bytes (+0.60%) +35 bytes
83658 bytes +498 bytes (+0.60%) +30 bytes
83660 bytes +500 bytes (+0.60%) +32 bytes
83628 bytes +468 bytes (+0.56%)
83632 bytes +472 bytes (+0.57%) +4 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 65051 bytes -18109 bytes (-21.78%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 72447 bytes -10713 bytes (-12.88%)
LZMA2 (Wikipedia) xz xz -9 73568 bytes -9592 bytes (-11.53%)
Brotli (Wikipedia) brotli brotli -q 11 73779 bytes -9381 bytes (-11.28%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 74205 bytes -8955 bytes (-10.77%)
Zstandard (Wikipedia) zstd zstd -19 79430 bytes -3730 bytes (-4.49%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 82193 bytes -967 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):


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.