Choose a version:
45% The original file has 325229 bytes (317.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 146390 bytes (143.0k, 45%).

After GZIP compression these minified files vary in size:
Boot
  58313 bytes (56.9k)
CDN, direct link
Baidu
  51325 bytes (50.1k)
CDN, direct link
cdnjs
  51314 bytes (50.1k)
CDN, direct link
unpkg
  50961 bytes (49.8k)
CDN, direct link
gzip -6 (default)
  50913 bytes (49.7k)
local copy
cdnhttps
  50875 bytes (49.7k)
CDN, direct link
gzip -9
  50728 bytes (49.5k)
local copy
libdeflate -12
  49113 bytes (48.0k)
local copy
7zip -mx=9 -tgzip
  49053 bytes (47.9k)
local copy
pigz -11 -n
  48843 bytes (47.7k)
local copy
kzip -s0 -rn -b6
  48813 bytes (47.7k)
local copy
Zopfli
  48722 bytes (47.6k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/d3/d3-3.3.11.min.js

You will automatically get the smallest D3 3.3.11 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 2153 bytes by using my D3 3.3.11 Zopfli version instead of the best available CDN (4.42% smaller than cdnhttps, 48722 vs. 50875 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 --i100000 --mb8 --mls8 --bsr20 --lazy --ohh

(found December 22, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 8  --mls8
block splitting recursion 20  --bsr20
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

Verify file integrity

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

MD5:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v3.3.11/d3.min.js --location | md5sum
f79090bdac5e153bda90001428664ea6  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-3.3.11.min.zopfli.js.gz | md5sum
f79090bdac5e153bda90001428664ea6  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v3.3.11/d3.min.js --location | sha1sum
7ab6cf48c423c65e705bfa99a75e96f968f3a114  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-3.3.11.min.zopfli.js.gz | sha1sum
7ab6cf48c423c65e705bfa99a75e96f968f3a114  -

These CDNs send you the original file:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 58313 bytes f79090bdac5e153bda90001428664ea6 (invalid)
cdnjs 51314 bytes f79090bdac5e153bda90001428664ea6 (invalid)
unpkg 50961 bytes f79090bdac5e153bda90001428664ea6 July 11, 2016 @ 16:31
cdnhttps 50875 bytes f79090bdac5e153bda90001428664ea6 December 24, 2015 @ 07:33

And some CDNs send you a different file:
CDN Size (compressed) MD5 (uncompressed) Comment / Diff Timestamp
Baidu 51325 bytes 30bad60a66785a6d4116e7e2fa55657d only whitespaces differ (invalid)

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

Other Versions

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

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
48722 bytes -4 bytes zopfli --i100000 --mls8 --bsr20 --lazy --ohh December 22, 2015 @ 10:17
48726 bytes -7 bytes zopfli --i10000 --mls8 --bsr20 --lazy --ohh October 14, 2015 @ 01:17
48733 bytes -20 bytes zopfli --i1000 --mls8 --bsr20 --lazy --ohh September 19, 2015 @ 15:54
48753 bytes zopfli --i100 --mls8 --bsr20 --lazy --ohh September 18, 2015 @ 21:06

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

Most recent activity on February 25, 2017 @ 23:43.

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 or 100,000.
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
48983 48986 48992 48877 48983 48908 48878 48892 48851 48859 49012 48883 49005 49007 49015
48825 48828 48829 48820 48887 48896 48861 48871 48811 48762 48769 48857 49009 49004 49011
48872 48845 48856 48759 48766 48865 48842 48797 48786 48813 48801 48760 49003 48998 48837
48843 48751 48767 48782 48763 48845 48850 48815 48820 48748 48752 48772 49006 49001 48834
48872 48801 48806 48781 48782 48858 48854 48803 48824 48750 48861 48773 49004 49002 48832
48867 48806 48804 48767 48778 48820 48851 48896 48815 48743 48745 48759 49005 48999 49003
48781 48752 48738 48770 48737 48873 48850 48807 48836 48844 48751 48923 48886 49010 48827
48870 48801 48801 48782 48850 48932 48851 48831 48894 48846 48854 48768 48988 48998 48848
48796 48765 48758 48767 48740 48881 48848 48800 48805 48747 48759 48758 49001 49002 48834
48789 48735 48789 48783 48763 48847 48847 48808 48812 48748 48750 48753 48991 48993 48791
48784 48789 48788 48765 48758 48840 48851 48809 48798 48747 48749 49007 48990 48995 48823
48788 48761 48787 48760 48758 48843 48856 48808 48811 48751 48748 48755 48993 49001 48852
48786 48742 48761 48757 48758 48842 48849 48835 48806 48749 48759 48755 49001 48994 48803
48789 48744 48759 48750 48763 48843 48852 48818 48815 48749 48749 48755 48989 48996 48820
48752 48765 48735 48762 48769 48870 48850 48814 48811 48750 48752 49005 48986 48996 49001
48783 48760 48759 48759 48760 48842 48846 48811 48847 48758 48749 49005 49000 48996 48984
48788 48763 48722 48760 48765 48849 48856 48807 48791 48760 48854 49006 48988 48997 48989
48762 48765 48734 48768 48783 48842 48849 48791 48805 48845 48859 49006 48988 48989 49000
48790 48766 48732 48766 48777 48871 48850 48830 48809 48763 48748 49005 49000 48999 49002
48792 48775 48760 48769 48764 48869 48845 48811 48801 48763 48761 49018 48999 48999 48853
48789 48754 48759 48758 48736 48826 48850 48805 48819 48750 48755 48760 49002 48911 48837
48779 48750 48759 48760 48731 48839 48831 48811 48801 48758 48777 48757 48994 48999 49004
48787 48737 48762 48765 48765 48882 48852 48817 48806 48757 48752 49004 48987 49002 48999

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 48753 bytes 100%
1,000 48733 bytes -20 bytes 100%
10,000 48726 bytes -7 bytes 100%
100,000 48722 bytes -4 bytes 0.29%
1,000,000
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
48961 bytes +239 bytes (+0.49%) +148 bytes
49043 bytes +321 bytes (+0.66%) +230 bytes
49045 bytes +323 bytes (+0.66%) +232 bytes
48959 bytes +237 bytes (+0.49%) +146 bytes
48969 bytes +247 bytes (+0.51%) +156 bytes
48875 bytes +153 bytes (+0.31%) +62 bytes
48813 bytes +91 bytes (+0.19%)
48825 bytes +103 bytes (+0.21%) +12 bytes
48832 bytes +110 bytes (+0.23%) +19 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 39016 bytes -9706 bytes (-19.92%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 41391 bytes -7331 bytes (-15.05%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 42105 bytes -6617 bytes (-13.58%)
Brotli (Wikipedia) brotli brotli -q 11 44132 bytes -4590 bytes (-9.42%)
LZMA2 (Wikipedia) xz xz -9 44796 bytes -3926 bytes (-8.06%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 46719 bytes -2003 bytes (-4.11%)
ZSTD (Wikipedia) zstd zstd -19 47198 bytes -1524 bytes (-3.13%)

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