mini-svg-data-uri

Mini SVG data: URI
====================

This tool converts SVGs into the most compact, compressible data: URI that SVG-supporting browsers tolerate. The results look like this (169 bytes):

``url
data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'
%3e%3cpath d='M22 38V51L32 32l19-19v12C44 26 43 10 38 0 52 15 49 39 22 38z'/%3e
%3c/svg%3e
`

Compare to the Base64 version (210 bytes):

`url
data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIH
ZpZXdCb3g9IjAgMCA1MCA1MCI+PHBhdGggZD0iTTIyIDM4VjUxTDMyIDMybDE5LTE5djEyQzQ0IDI2ID
QzIDEwIDM4IDAgNTIgMTUgNDkgMzkgMjIgMzh6Ii8+PC9zdmc+
`

Or the URL-encoded version other tools produce (256 bytes):

`url
data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%
2F2000%2Fsvg%22%20viewBox%3D%220%200%2050%2050%22%3E%3Cpath%20d%3D%22M22%2038V51
L32%2032l19-19v12C44%2026%2043%2010%2038%200%2052%2015%2049%2039%2022%2038z%22%2
F%3E%3C%2Fsvg%3E
`

For a more realistic example, I inlined the icons from the Open Iconic project into CSS files with the 3 above methods:

| Compression | Base64 | Basic %-encoding | mini-svg-data-uri |
|-------------|----------:|-----------------:|--------------------:|
| None | 96.459 kB | 103.268 kB | 76.583 kB |
| gzip -9 | 17.902 kB | 13.780 kB | 12.974 kB |
| brotli -Z | 15.797 kB | 11.693 kB | 10.976 kB |

Roughly 6% smaller compressed, but don't write off the ≈20% uncompressed savings either. Some browser caches decompress before store, and parsing time/memory usage scale linearly with uncompressed filesize.


Usage
-----

`js
var svgToMiniDataURI = require('mini-svg-data-uri');

var svg = '';

var optimizedSVGDataURI = svgToMiniDataURI(svg);
// "data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'%3e%3cpath d='M22 38V51L32 32l19-19v12C44 26 43 10 38 0 52 15 49 39 22 38z'/%3e%3c/svg%3e"
`

You can also try it in your browser at RunKit.

$3

If you have it installed globally, or as some kind of dependency inside your project’s directory:

`sh
mini-svg-data-uri file.svg # writes to stdout
mini-svg-data-uri file.svg file.svg.uri # writes to the given output filename
`

Use --help for more info.

$3

* This does not optimize the SVG source file. You’ll want svgo or its brother SVGOMG for that.

* The default output does not work inside srcset attributes. Use the .toSrcset method for that:

`js
var srcsetExample = html



;
`

* The resulting Data URI should be wrapped with double quotes: url("…"), , etc.

* This might change or break SVGs that use " in character data, like inside or aria-label or something. Try curly quotes (“”) or " instead.


FAQ
---

$3

charset does nothing for Data URIs. The URI can only be the encoding of its parent file — it’s included in it!

$3

It compresses slightly better. No, really. Using the same files from earlier:

| Compression | Uppercase (%AF) | Lowercase (%af) |
|-------------|------------------:|------------------:|
| gzip -9 | 12.978 kB | 12.974 kB |
| brotli -Z` | 10.988 kB | 10.976 kB |

I did say slightly.

Browser support
---------------

* Internet Explorer 9 and up, including Edge
* Firefox, Safari, Chrome, whatever else uses their engines
* Android WebKit 3+
* Opera Mini’s server-side Presto