Choose a version:
48% The original file has 508018 bytes (496.1k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 243285 bytes (237.6k, 48%).

After GZIP compression these minified files vary in size:
Boot
  80354 bytes (78.5k)
CDN
cdnjs
  80354 bytes (78.5k)
CDN
gzip -6 (default)
  79647 bytes (77.8k)
local copy
gzip -9
  79347 bytes (77.5k)
local copy
libdeflate -12
  76193 bytes (74.4k)
local copy
7zip -mx=9 -tgzip
  75608 bytes (73.8k)
local copy
pigz -11 -n
  75256 bytes (73.5k)
local copy
Zopfli
  75188 bytes (73.4k)
local copy
Zopfli (defluff)
  75187 bytes (73.4k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/d3/d3-5.9.5.min.js (or via HTTPS)

You will automatically get the smallest D3 5.9.5 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 5166 bytes by using my D3 5.9.5 Zopfli version instead of the best available CDN (6.87% smaller than cdnjs, 75188 vs. 80354 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 July 6, 2019)
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 (75187 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/v5.9.5/d3.zip --location | md5sum
1e2606a9f2d30d7890120f519c8f4fa4  -
curl --silent --compressed https://minime.stephan-brumme.com/files/d3/d3-5.9.5.min.zopfli.js.gz | md5sum
1e2606a9f2d30d7890120f519c8f4fa4  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v5.9.5/d3.zip --location | sha1sum
f1d49706dc7adb6419582f4b99a1270b5a9f4108  -
curl --silent --compressed https://minime.stephan-brumme.com/files/d3/d3-5.9.5.min.zopfli.js.gz | sha1sum
f1d49706dc7adb6419582f4b99a1270b5a9f4108  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 80354 bytes 1e2606a9f2d30d7890120f519c8f4fa4 June 29, 2019 @ 12:46
cdnjs 80354 bytes 1e2606a9f2d30d7890120f519c8f4fa4 June 29, 2019 @ 12:46

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

Other Versions

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

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
75188 bytes -4 bytes zopfli --i1000000 --mls8192 --bsr12 --lazy --ohh July 6, 2019 @ 00:26
75192 bytes -2 bytes zopfli --i100000 --mls8192 --bsr12 --lazy --ohh July 5, 2019 @ 12:45
75194 bytes -3 bytes zopfli --i100000 --mls8192 --bsr11 --lazy --ohh July 5, 2019 @ 09:17
75197 bytes -1 byte zopfli --i10000 --mls8192 --bsr12 --lazy --ohh July 4, 2019 @ 03:23
75198 bytes -1 byte zopfli --i10000 --mls8192 --bsr18 --lazy --ohh July 4, 2019 @ 02:45
75199 bytes -2 bytes zopfli --i10000 --mls8192 --bsr16 --lazy --ohh July 3, 2019 @ 19:45
75201 bytes -1 byte zopfli --i10000 --mls8192 --bsr23 --lazy --ohh July 3, 2019 @ 19:35
75202 bytes -8 bytes zopfli --i10000 --mls8192 --bsr30 --lazy --ohh July 3, 2019 @ 18:39
75210 bytes -2 bytes zopfli --i1000 --mls8192 --bsr30 --lazy --ohh July 3, 2019 @ 13:34
75212 bytes -2 bytes zopfli --i1000 --mls512 --bsr6 --lazy --ohh July 3, 2019 @ 13:11
75214 bytes -1 byte zopfli --i1000 --mls4096 --bsr18 --lazy --ohh July 3, 2019 @ 12:18
75215 bytes -9 bytes zopfli --i1000 --mls4096 --bsr14 --lazy --ohh July 3, 2019 @ 12:03
75224 bytes -15 bytes zopfli --i1000 --mls64 --bsr40 --lazy --ohh July 3, 2019 @ 12:01
75239 bytes zopfli --i100 --mls8192 --bsr22 --lazy --ohh July 3, 2019 @ 11:55

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

Most recent activity on July 8, 2019 @ 10:35.

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
75650 75641 75725 75637 75638 75650 75653 75388 75549 75402 75612 75406 75422 75448 75455
75273 75526 75766 75646 75479 75243 75444 75441 75673 75279 75249 75312 75322 75286 75403
75441 75226 75436 75425 75437 75222 75222 75446 75205 75317 75247 75229 75261 75402 75353
75434 75523 75226 75229 75451 75417 75221 75227 75204 75230 75222 75404 75281 75330 75276
75420 75414 75628 75646 75273 75275 75277 75517 75400 75440 75333 75340 75347 75351 75297
75544 75513 75515 75436 75225 75224 75240 75423 75423 75226 75218 75203 75384 75353 75337
75418 75519 75451 75422 75433 75216 75209 75232 75405 75223 75207 75207 75384 75453 75274
75430 75431 75217 75600 75226 75419 75228 75286 75402 75259 75222 75201 75194 75331 75333
75524 75520 75548 75220 75430 75224 75414 75227 75398 75226 75231 75205 75188 75343 75332
75523 75225 75542 75434 75220 75212 75208 75409 75402 75225 75229 75230 75389 75481 75258
75521 75519 75442 75511 75428 75214 75416 75417 75401 75446 75224 75206 75407 75361 75259
75525 75519 75543 75569 75431 75238 75432 75425 75404 75220 75228 75212 75205 75336 75267
75529 75514 75542 75223 75433 75228 75226 75231 75401 75230 75204 75207 75199 75348 75302
75545 75519 75540 75221 75509 75218 75248 75230 75400 75222 75236 75205 75200 75360 75332
75221 75224 75219 75223 75238 75221 75230 75228 75419 75224 75221 75202 75198 75329 75274
75524 75521 75440 75226 75223 75222 75418 75229 75408 75222 75217 75210 75384 75354 75259
75527 75521 75544 75522 75431 75217 75413 75417 75399 75257 75220 75205 75379 75335 75353
75526 75524 75540 75226 75223 75217 75416 75414 75398 75408 75219 75202 75402 75416 75332
75534 75532 75541 75413 75429 75217 75218 75414 75403 75410 75232 75207 75202 75342 75244
75524 75522 75542 75231 75233 75217 75415 75414 75405 75225 75220 75207 75201 75341 75274
75229 75228 75242 75431 75239 75213 75208 75411 75402 75232 75204 75209 75205 75343 75274
75522 75519 75546 75522 75229 75212 75212 75418 75403 75411 75223 75212 75202 75343 75335
75527 75526 75543 75530 75431 75214 75409 75228 75407 75230 75227 75205 75384 75386 75279

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 75234 bytes 100%
1,000 75210 bytes -24 bytes 100%
10,000 75197 bytes -13 bytes 100%
100,000 75192 bytes -5 bytes 0.58%
1,000,000 75188 bytes -4 bytes 0.29%
10,000,000

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 59325 bytes -15863 bytes (-21.10%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 66032 bytes -9156 bytes (-12.18%)
LZMA2 (Wikipedia) xz xz -9 66884 bytes -8304 bytes (-11.04%)
Brotli (Wikipedia) brotli brotli -q 11 67136 bytes -8052 bytes (-10.71%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 68767 bytes -6421 bytes (-8.54%)
Zstandard (Wikipedia) zstd zstd -19 72301 bytes -2887 bytes (-3.84%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 74883 bytes -305 bytes (-0.41%)

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 2019.
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