Choose a version:
47% The original file has 452249 bytes (441.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 214693 bytes (209.7k, 47%).

After GZIP compression these minified files vary in size:
Boot
  82621 bytes (80.7k)
CDN
cdnjs
  73137 bytes (71.4k)
CDN
gzip -6 (default)
  72673 bytes (71.0k)
local copy
jsdelivr
  72518 bytes (70.8k)
CDN
gzip -9
  72389 bytes (70.7k)
local copy
libdeflate -12
  69692 bytes (68.1k)
local copy
7zip -mx=9 -tgzip
  69292 bytes (67.7k)
local copy
kzip -s0 -rn -b8
  69025 bytes (67.4k)
local copy
pigz -11 -n
  68832 bytes (67.2k)
local copy
Zopfli
  68770 bytes (67.2k)
local copy
Zopfli (defluff)
  68769 bytes (67.2k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/d3/d3-4.6.0.min.js

You will automatically get the smallest D3 4.6.0 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 3748 bytes by using my D3 4.6.0 Zopfli version instead of the best available CDN (5.45% smaller than jsdelivr, 68770 vs. 72518 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 --bsr9 --lazy --ohh

(found May 3, 2017)
Description Value Parameter
iterations 1000000  --i1000000
maximum blocks 8  --mb8
maximum length score 512  --mls512
block splitting recursion 9  --bsr9
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 (68769 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/v4.6.0/d3.zip --location | md5sum
37f8b8da73d69018fb6a538225cecae8  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-4.6.0.min.zopfli.js.gz | md5sum
37f8b8da73d69018fb6a538225cecae8  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v4.6.0/d3.zip --location | sha1sum
712220921b15aec468fd1421e3dfa19bf005c12b  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-4.6.0.min.zopfli.js.gz | sha1sum
712220921b15aec468fd1421e3dfa19bf005c12b  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 82621 bytes 37f8b8da73d69018fb6a538225cecae8 February 27, 2017 @ 18:44
cdnjs 73137 bytes 37f8b8da73d69018fb6a538225cecae8 February 19, 2017 @ 18:18
jsdelivr 72518 bytes 37f8b8da73d69018fb6a538225cecae8 February 19, 2017 @ 18:33

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

Other Versions

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

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
68770 bytes -2 bytes zopfli --i1000000 --mls512 --bsr9 --lazy --ohh May 3, 2017 @ 03:14
68772 bytes -10 bytes zopfli --i100000 --mls512 --bsr9 --lazy --ohh May 2, 2017 @ 11:37
68782 bytes -7 bytes zopfli --i10000 --mls512 --bsr9 --lazy --ohh April 29, 2017 @ 00:27
68789 bytes -1 byte zopfli --i10000 --mls512 --bsr11 --lazy --ohh April 28, 2017 @ 20:47
68790 bytes -3 bytes zopfli --i10000 --mls64 --bsr25 --lazy --ohh April 28, 2017 @ 20:31
68793 bytes -6 bytes zopfli --i1000 --mls512 --bsr9 --lazy --ohh April 28, 2017 @ 15:37
68799 bytes -21 bytes zopfli --i1000 --mls512 --bsr23 --lazy --ohh April 28, 2017 @ 15:32
68820 bytes zopfli --i100 --mls32 --bsr21 --lazy --ohh April 28, 2017 @ 14:41

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

Most recent activity on May 3, 2017 @ 11:05.

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
69191 69284 69137 69075 69201 69146 69115 69035 69059 69075 69053 69030 69015 69017 69055
69071 69065 68964 69075 69005 68878 68873 68823 68793 68980 68946 68966 68963 68955 68947
68851 68799 68937 68840 68813 68929 68817 68792 68814 68949 68938 68954 68947 68973 68966
68931 68795 68803 68795 68848 68795 68960 69170 68805 68934 68937 68956 68970 68953 68947
68886 68809 68821 68874 68876 68795 68961 68929 68994 68945 68937 68934 68940 68968 68967
68932 68795 68794 68795 68882 68928 68929 68923 68770 68920 68946 68962 68953 68953 68959
68930 68872 68845 68849 69855 68933 68978 68936 68920 68917 68956 68961 68957 68948 68939
68844 68853 68934 68922 68919 68878 68967 68967 68783 68939 68934 68942 68951 68952 68953
68933 68931 68917 68843 68797 68782 68976 68928 68813 68938 68936 68953 68961 68947 68956
68932 68796 68807 68915 69827 68972 69855 69851 68923 68918 68963 68938 68954 68937 68965
68871 68934 68894 68792 69853 68929 68959 68926 68791 68918 68940 68955 68964 68954 68972
68930 68933 68793 68795 68795 68846 68963 68936 68793 68932 68933 68954 68959 68935 68966
68959 68818 68892 68795 69853 68961 68964 68932 68794 68908 68934 68969 68963 68926 68963
68930 68794 68797 68799 68796 68969 68928 68933 68796 68959 68900 68960 68956 68952 68963
68806 69871 68794 68793 68933 68927 68962 68932 68926 68981 68942 68958 68905 68949 68934
68847 68846 68799 68797 68997 68920 68933 68964 68921 68900 68948 68955 68945 68930 68952
68848 68930 68913 68797 69851 69003 68963 68934 68923 68925 68905 68959 68937 68937 68931
68873 68797 68796 68973 68794 68824 68959 68975 68916 68900 68899 68953 68934 68936 68911
68846 68795 68934 68795 68884 68967 69857 68934 68921 68905 68907 68957 68907 68917 68925
68933 68931 68798 68798 68795 68792 68938 68999 68791 68793 68907 68957 68924 68937 68905
68934 68796 68797 68912 69000 68790 68970 69007 68791 68900 68908 68924 68916 68946 68906
68931 68843 68823 68843 68883 69865 69857 68948 68946 68920 68904 68917 68930 69057 68938
68934 68935 68792 68873 68973 68800 69009 68911 69871 68926 68899 68899 68905 68923 68930

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 68820 bytes 100%
1,000 68793 bytes -27 bytes 100%
10,000 68782 bytes -11 bytes 100%
100,000 68772 bytes -10 bytes 0.87%
1,000,000 68770 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
69038 bytes +268 bytes (+0.39%) +13 bytes
70343 bytes +1573 bytes (+2.29%) +1318 bytes
70026 bytes +1256 bytes (+1.83%) +1001 bytes
69157 bytes +387 bytes (+0.56%) +132 bytes
69042 bytes +272 bytes (+0.40%) +17 bytes
69051 bytes +281 bytes (+0.41%) +26 bytes
69066 bytes +296 bytes (+0.43%) +41 bytes
69026 bytes +256 bytes (+0.37%) +1 byte
69025 bytes +255 bytes (+0.37%)

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 54078 bytes -14692 bytes (-21.36%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 60143 bytes -8627 bytes (-12.54%)
LZMA2 (Wikipedia) xz xz -9 60968 bytes -7802 bytes (-11.35%)
Brotli (Wikipedia) brotli brotli -q 11 61157 bytes -7613 bytes (-11.07%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 62101 bytes -6669 bytes (-9.70%)
ZSTD (Wikipedia) zstd zstd -19 66441 bytes -2329 bytes (-3.39%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 67581 bytes -1189 bytes (-1.73%)

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