Choose a version:
48% The original file has 508030 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 243293 bytes (237.6k, 48%).

After GZIP compression these minified files vary in size:
Boot
  80361 bytes (78.5k)
CDN
cdnjs
  80361 bytes (78.5k)
CDN
gzip -6 (default)
  79653 bytes (77.8k)
local copy
gzip -9
  79353 bytes (77.5k)
local copy
libdeflate -12
  76205 bytes (74.4k)
local copy
7zip -mx=9 -tgzip
  75612 bytes (73.8k)
local copy
pigz -11 -n
  75257 bytes (73.5k)
local copy
Zopfli
  75181 bytes (73.4k)
local copy
Zopfli (defluff)
  75179 bytes (73.4k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/d3/d3-5.9.6.min.js (or via HTTPS)

You will automatically get the smallest D3 5.9.6 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 5180 bytes by using my D3 5.9.6 Zopfli version instead of the best available CDN (6.89% smaller than cdnjs, 75181 vs. 80361 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 --mls32768 --bsr6 --lazy --ohh

(found July 6, 2019)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 32768  --mls32768
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 2 more bytes (75179 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/v5.9.6/d3.zip --location | md5sum
dc99f82dd47d7c94d66e8686394d822d  -
curl --silent --compressed https://minime.stephan-brumme.com/files/d3/d3-5.9.6.min.zopfli.js.gz | md5sum
dc99f82dd47d7c94d66e8686394d822d  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v5.9.6/d3.zip --location | sha1sum
61571c5304b578b61103660c18b96f0c001910f3  -
curl --silent --compressed https://minime.stephan-brumme.com/files/d3/d3-5.9.6.min.zopfli.js.gz | sha1sum
61571c5304b578b61103660c18b96f0c001910f3  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 80361 bytes dc99f82dd47d7c94d66e8686394d822d June 29, 2019 @ 12:46
cdnjs 80361 bytes dc99f82dd47d7c94d66e8686394d822d 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
75181 bytes -2 bytes zopfli --i1000000 --mls32768 --bsr6 --lazy --ohh July 6, 2019 @ 02:48
75183 bytes -9 bytes zopfli --i100000 --mls32768 --bsr6 --lazy --ohh July 5, 2019 @ 12:47
75192 bytes -9 bytes zopfli --i10000 --mls32768 --bsr6 --lazy --ohh July 4, 2019 @ 02:55
75201 bytes -13 bytes zopfli --i1000 --mls32768 --bsr6 --lazy --ohh July 3, 2019 @ 15:37
75214 bytes -3 bytes zopfli --i1000 --mls4096 --bsr14 --lazy --ohh July 3, 2019 @ 12:49
75217 bytes -7 bytes zopfli --i1000 --mls8192 --bsr17 --lazy --ohh July 3, 2019 @ 12:19
75224 bytes -1 byte zopfli --i1000 --mls2048 --bsr10 --lazy --ohh July 3, 2019 @ 12:13
75225 bytes -11 bytes zopfli --i1000 --mls4096 --bsr25 --lazy --ohh July 3, 2019 @ 12:10
75236 bytes -4 bytes zopfli --i1000 --mls64 --bsr30 --lazy --ohh July 3, 2019 @ 12:08
75240 bytes zopfli --i100 --mls8192 --bsr17 --lazy --ohh July 3, 2019 @ 12:07

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 @ 10:39.

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
75661 75650 75738 75651 75645 75660 75666 75393 75559 75410 75621 75414 75429 75459 75707
75532 75525 75674 75654 75315 75249 75449 75461 75690 75250 75267 75311 75329 75436 75412
75449 75230 75443 75432 75447 75222 75235 75442 75233 75323 75267 75235 75266 75352 75181
75437 75530 75243 75572 75458 75218 75413 75418 75210 75240 75227 75437 75289 75336 75337
75244 75415 75537 75660 75279 75284 75282 75526 75410 75275 75340 75346 75352 75353 75445
75250 75520 75521 75438 75232 75218 75240 75256 75427 75233 75226 75225 75392 75358 75404
75424 75526 75457 75229 75235 75217 75217 75239 75407 75230 75213 75211 75393 75447 75283
75567 75435 75224 75617 75437 75224 75234 75289 75412 75232 75230 75208 75347 75336 75343
75524 75527 75550 75230 75437 75226 75418 75233 75406 75234 75235 75214 75198 75352 75337
75531 75231 75552 75435 75229 75219 75418 75412 75413 75230 75213 75214 75392 75499 75304
75530 75531 75550 75534 75436 75221 75218 75417 75420 75263 75229 75206 75412 75369 75345
75531 75523 75551 75252 75428 75239 75445 75435 75413 75237 75237 75210 75209 75353 75254
75534 75523 75550 75235 75421 75218 75230 75229 75407 75223 75228 75209 75207 75355 75285
75549 75528 75464 75355 75238 75224 75236 75233 75413 75233 75237 75212 75207 75372 75341
75230 75527 75227 75231 75242 75228 75235 75233 75414 75226 75229 75210 75198 75207 75283
75529 75527 75440 75233 75230 75223 75425 75233 75409 75234 75231 75210 75391 75400 75267
75535 75545 75550 75536 75440 75223 75417 75418 75409 75258 75227 75208 75389 75392 75360
75534 75531 75547 75234 75219 75215 75421 75418 75404 75414 75224 75213 75413 75421 75343
75541 75538 75549 75423 75439 75226 75422 75416 75412 75414 75236 75209 75209 75349 75304
75531 75531 75549 75234 75240 75228 75422 75418 75417 75446 75226 75210 75207 75349 75368
75451 75229 75250 75533 75230 75224 75415 75415 75410 75230 75224 75214 75209 75347 75268
75528 75525 75550 75527 75235 75223 75417 75419 75408 75416 75232 75213 75207 75351 75343
75533 75528 75524 75532 75442 75216 75417 75412 75415 75232 75229 75213 75390 75392 75285

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 75216 bytes 100%
1,000 75201 bytes -15 bytes 100%
10,000 75192 bytes -9 bytes 100%
100,000 75183 bytes -9 bytes 0.87%
1,000,000 75181 bytes -2 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 59332 bytes -15849 bytes (-21.08%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 66048 bytes -9133 bytes (-12.15%)
LZMA2 (Wikipedia) xz xz -9 66912 bytes -8269 bytes (-11.00%)
Brotli (Wikipedia) brotli brotli -q 11 67059 bytes -8122 bytes (-10.80%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 68779 bytes -6402 bytes (-8.52%)
Zstandard (Wikipedia) zstd zstd -19 72308 bytes -2873 bytes (-3.82%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 74862 bytes -319 bytes (-0.42%)

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