Choose a version:
45% The original file has 335497 bytes (327.6k) and is available from the project website.
There you can find the official minified version, too, which brings down the size to 150760 bytes (147.2k, 45%).

After GZIP compression these minified files vary in size:
Boot
  60731 bytes (59.3k)
CDN, direct link
jsdelivr
  60731 bytes (59.3k)
CDN, direct link
cdnjs
  53638 bytes (52.4k)
CDN, direct link
unpkg
  53342 bytes (52.1k)
CDN, direct link
gzip -6 (default)
  53222 bytes (52.0k)
local copy
cdnhttps
  53217 bytes (52.0k)
CDN, direct link
gzip -9
  53067 bytes (51.8k)
local copy
libdeflate -12
  51375 bytes (50.2k)
local copy
7zip -mx=9 -tgzip
  51357 bytes (50.2k)
local copy
pigz -11 -n
  51073 bytes (49.9k)
local copy
kzip -s0 -rn -b7
  51048 bytes (49.9k)
local copy
Zopfli
  50983 bytes (49.8k)
local copy
Zopfli (defluff)
  50981 bytes (49.8k)
local copy

perma-link to the smallest file on my server:
http://minime.stephan-brumme.com/files/d3/d3-3.5.3.min.js

You will automatically get the smallest D3 3.5.3 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 2234 bytes by using my D3 3.5.3 Zopfli version instead of the best available CDN (4.38% smaller than cdnhttps, 50983 vs. 53217 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 --mls2048 --bsr20 --lazy --ohh

(found September 25, 2015)
Description Value Parameter
iterations 100000  --i100000
maximum blocks 8  --mb8
maximum length score 2048  --mls2048
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

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 (50981 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/v3.5.3/d3.min.js --location | md5sum
81897cbac8496a55abbef47f0a615669  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-3.5.3.min.zopfli.js.gz | md5sum
81897cbac8496a55abbef47f0a615669  -

SHA1:
curl --silent --compressed https://raw.githubusercontent.com/mbostock/d3/v3.5.3/d3.min.js --location | sha1sum
ab433e47218ff02114a6fe344b7e4b29cc12683d  -
curl --silent --compressed http://minime.stephan-brumme.com/files/d3/d3-3.5.3.min.zopfli.js.gz | sha1sum
ab433e47218ff02114a6fe344b7e4b29cc12683d  -

All listed CDNs deliver identical contents:
CDN Size (compressed) MD5 (uncompressed) Timestamp
Boot 60731 bytes 81897cbac8496a55abbef47f0a615669 (invalid)
jsdelivr 60731 bytes 81897cbac8496a55abbef47f0a615669 (invalid)
cdnjs 53638 bytes 81897cbac8496a55abbef47f0a615669 (invalid)
unpkg 53342 bytes 81897cbac8496a55abbef47f0a615669 July 11, 2016 @ 16:30
cdnhttps 53217 bytes 81897cbac8496a55abbef47f0a615669 December 24, 2015 @ 07:33

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

Other Versions

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

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
50983 bytes -5 bytes zopfli --i100000 --mls2048 --bsr20 --lazy --ohh September 25, 2015 @ 17:22
50988 bytes -9 bytes zopfli --i10000 --mls2048 --bsr20 --lazy --ohh September 25, 2015 @ 16:08
50997 bytes -1 byte zopfli --i1000 --mls2048 --bsr20 --lazy --ohh September 19, 2015 @ 01:50
50998 bytes -7 bytes zopfli --i1000 --mls1024 --bsr20 --lazy --ohh September 19, 2015 @ 01:47
51005 bytes -3 bytes zopfli --i1000 --mls1024 --bsr10 --lazy --ohh September 19, 2015 @ 01:47
51008 bytes -3 bytes zopfli --i1000 --mls8 --bsr20 --lazy --ohh September 19, 2015 @ 01:28
51011 bytes -4 bytes zopfli --i1000 --mls8 --bsr10 --lazy --ohh September 19, 2015 @ 01:24
51015 bytes -7 bytes zopfli --i1000 --mls8 --bsr12 --lazy --ohh September 19, 2015 @ 01:20
51022 bytes zopfli --i100 --mls2048 --bsr20 --lazy --ohh September 18, 2015 @ 21:22

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

Most recent activity on February 20, 2017 @ 16:40.

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
51176 51177 51194 51174 51176 51165 51169 51165 51119 51252 51271 51146 51270 51255 51266
51104 51022 51040 51048 51066 51101 51069 51035 51026 51045 51262 51149 51261 51133 51038
51062 51042 51016 51025 51068 51036 51144 51020 51023 51035 51260 51112 51265 51259 51263
51049 51055 51028 51060 51085 51021 51086 51033 51021 51014 51012 51116 51263 51011 51261
51088 51075 51046 51061 51083 51072 51112 51015 51005 51024 51258 51129 51274 51047 51261
51096 51062 51031 51070 51106 51024 51120 51050 51026 51007 51008 51122 51259 51021 51043
51042 51038 50999 51060 51178 51057 51028 51029 51013 50998 51263 51122 51257 51030 51260
51074 51010 51016 51062 51033 51026 51058 51038 51018 51011 51000 51106 51265 51121 51260
51097 51007 51009 51061 51022 51045 51147 51028 51008 51007 51000 51111 51255 51025 51038
51093 51057 51036 51013 51035 51022 51055 51035 51009 51025 50993 51112 51262 51025 51046
51046 51053 51026 51061 51079 51023 51054 51015 51006 51022 51010 51101 51260 51013 51049
51094 51066 51038 51057 51027 51022 51087 51078 51006 51021 50987 51105 51258 51011 51261
51072 51046 51036 51061 51078 51024 51092 51035 51004 51007 51262 51114 51259 51024 51037
50996 51008 51014 51045 51074 51031 51092 51030 51015 51008 51006 51124 51259 51008 51034
51099 51020 51027 51090 51026 51031 51057 51081 51007 51026 51262 51131 51263 51008 51037
51109 51048 51024 51064 51079 51030 51090 51044 51008 51023 51088 51106 51260 51021 51042
51094 51068 51003 51043 51076 51026 51054 51036 51013 50992 50983 51101 51259 51020 51069
51092 51058 51012 51041 51078 51030 51194 51030 51006 51009 51073 51124 51259 51020 51040
51057 51032 51037 51087 51071 51038 51053 51109 51024 51001 50992 51104 51263 51025 51037
51097 51055 51027 51061 51056 51030 51094 51033 51005 51022 50993 51099 51259 51023 51040
51052 51067 51027 51046 51031 51049 51122 51036 51005 51021 51074 51111 51259 51022 51037
51092 51058 51029 51066 51027 51031 51099 51028 50995 50999 51006 51112 51255 51021 51039
51043 51077 51032 51066 51066 51023 51120 51031 51015 50996 51008 51115 51259 51015 51043

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 51022 bytes 100%
1,000 50997 bytes -25 bytes 100%
10,000 50988 bytes -9 bytes 100%
100,000 50983 bytes -5 bytes 0.58%
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
51300 bytes +317 bytes (+0.62%) +252 bytes
51299 bytes +316 bytes (+0.62%) +251 bytes
51306 bytes +323 bytes (+0.63%) +258 bytes
51246 bytes +263 bytes (+0.52%) +198 bytes
51192 bytes +209 bytes (+0.41%) +144 bytes
51193 bytes +210 bytes (+0.41%) +145 bytes
51099 bytes +116 bytes (+0.23%) +51 bytes
51048 bytes +65 bytes (+0.13%)
51066 bytes +83 bytes (+0.16%) +18 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 40699 bytes -10284 bytes (-20.17%)
RAR (proprietary) RAR rar a -m5 -md64m -mc63:128t -mt1 43298 bytes -7685 bytes (-15.07%)
PPMd (Wikipedia) 7zip 7za a -mx=9 -m0=ppmd 44360 bytes -6623 bytes (-12.99%)
Brotli (Wikipedia) brotli brotli -q 11 46046 bytes -4937 bytes (-9.68%)
LZMA2 (Wikipedia) xz xz -9 46820 bytes -4163 bytes (-8.17%)
Burrows-Wheeler transform (Wikipedia) bzip2 bzip2 -9 48746 bytes -2237 bytes (-4.39%)
ZSTD (Wikipedia) zstd zstd -19 49297 bytes -1686 bytes (-3.31%)

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