v4.0.0-rc.1

Release Candidate

This is a release candidate. We are still working on v4.0.0, and API stability isn't guaranteed, though we'll aim to keep it fairly consistent.

You can try this build by installing or depending on svgo@4.0.0-rc.1, or svgo@rc.

Please report any problems you encounter in the GitHub issue tracker. 👍🏽

Refer to the release notes of previous v4.0.0 release candidates to get the full context, this will only describe the differences since the previous release candidate.

Imports/Exports

We now use the exports field in package.json to define the public interface of the package. However, we received feedback from users who make custom plugins that they depended on some of our other types and helpers.

The types (XastNode, etc.) should've been exported, which has now been resolved.

Some of our functions like querySelector and querySelectorAll were not actually intended to be part of our public API. As our README.md suggests, the API usage primarily entails optimize and loadConfig. However, there are valid use cases for this, so we'll export the ones that are frequently used and continue and ensure backward compatibility to make plugin development easier, and for ease of migration between v3 and v4.

This means users that develop custom plugins will have stronger API guarantees when using querySelector, querySelectorAll, and _collections. However, they should be imported from svgo or svgo/browser now.

- import { querySelector, querySelectorAll } from 'svgo/lib/xast.js';
+ import { querySelector, querySelectorAll } from 'svgo';

- import _collections from 'svgo/plugins/_collections';
+ import { _collections } from 'svgo';

// For TypeScript users!
- import type { XastElement, XastRoot, XastChild } from 'svgo/lib/types';
+ import type { XastElement, XastRoot, XastChild } from 'svgo';

v4.0.0-rc.0

Release Candidate

This is a release candidate. We are still working on v4.0.0, and API stability isn't guaranteed, though we'll aim to keep it fairly consistent.

You can try this build by installing or depending on svgo@4.0.0-rc.0, or svgo@rc.

Please report any problems you encounter in the GitHub issue tracker. 👍🏽

Breaking Changes

A brief summary, if you use the browser bundle of SVGO, or import/require anything except the base svgo path, such as svgo/lib/builtin, then you will very likely have to make code changes to update to version 4.

Dropping Support for Node.js v14

Node.js v14 is no longer supported by the Node.js team, including security support from 30 April 2023. Node.js v16 is no longer supported too, but as many are still using it, we'll continue to support Node.js v16 for now.

This allows us to update our dependencies to more recent versions, and to access more modern Node.js APIs.

Node.js v14 may still work at the time of this release based, but we will no longer be testing against v14 from now on.

Imports/Exports

We use the exports field in package.json to define the public interface of the package. This enforces boundaries between the intended public API and any internal structures/helpers that we use internally.

There are two ways to import SVGO:

• svgo - for normal usage, such as scripts or server-side applications.
• svgo/browser - for in-browser usage.

If you use the browser bundle, you must amend how you import it:

- import { optimize } from "svgo/dist/svgo.browser.js";
+ import { optimize } from "svgo/browser";

For all interfaces, you can import the default export which yields an object with all exported properties, or destruct while importing to get an individual property:

// default.mjs
import SVGO from 'svgo';
console.log(SVGO.VERSION); // 4.0.0-rc.0

// destruct.mjs
import { VERSION } from 'svgo';
console.log(VERSION);  // 4.0.0-rc.0

// default.cjs
const SVGO = require('svgo');
console.log(SVGO.VERSION);  // 4.0.0-rc.0

// destruct.cjs
const { VERSION } = require('svgo');
console.log(VERSION); // 4.0.0-rc.0

// browser.mjs
import SVGO from 'svgo/browser';
console.log(SVGO.VERSION); // 4.0.0-rc.0

We support 3 environments, ESM, Common JS, and browser. The table below describes the properties that are available in each environment (excludes types):

	ESM	Common JS	Browser
VERSION	✅	✅	✅
optimize	✅	✅	✅
builtinPlugins	✅	✅	✅
loadConfig	✅	✅

Importing Plugins

If you import/require the array of built-in plugins, or a single plugin during runtime, this is now a top-level export instead:

// builtin.mjs - get an array of all built-in plugins
- import { builtin } from 'svgo/lib/builtin';
+ import { builtinPlugins } from 'svgo'

// plugin.mjs - get a single plugin
- import presetDefault from 'svgo/plugins/preset-default';
+ import { builtinPlugins } from 'svgo';
+ const prefixDefault = builtinPlugins.find(plugin => plugin.name === 'preset-default');

// plugin-map.mjs - get all plugins as a map using the plugin name as a key
import { builtinPlugins } from 'svgo';
const pluginMap = builtinPlugins.reduce((acc, val) => acc.set(val.name, val), new Map());

Default Plugins

Both removeViewBox and removeTitle have been disabled by default. Both have been major pain points for users, and don't make sense to enable in most cases. Other libraries wrapping SVGO have also been disabling these plugins by default, such as Docusaurus and SVGR.

• removeViewBox removes the scalability of SVGs, which is unexpected given the S stands for scalable.
• removeTitle reduces accessibility, which preserving accessibility is more important than optimization.

If you would like either of these plugins enabled, you can do so by configuring it in the SVGO config, see the README for more context:

  export default {
    plugins: [
      'preset-default', // built-in plugins enabled by default
+     'removeViewBox',
+     'removeTitle',
    ],
  };

removeScriptElement → removeScripts

The removeScriptElement plugin has been renamed to removeScripts, to more accurately reflect what the plugin does. It does not only remove the <script> tag, but also event handlers and script URIs from links.

To migrate, amend your SVGO config to refer to removeScripts instead if you use that plugin.

  export default {
    plugins: [
      'preset-default', // built-in plugins enabled by default
-     'removeScriptElement',
+     'removeScripts',
    ],
  };

---

What Else

ESM

SVGO is now a dual package, serving for both Common JS and ESM usage. To be more explicit, SVGO will continue to work in Common JS projects!

Thanks to @jdufresne for doing the bulk of the work.

Default Behavior

• convertColors, now converts all references to colors excluding references to IDs to lowercase. This can be disabled by setting convertCase to false.

Bug Fixes

• cleanupIds, treat both URI encoded and non-URI encoded IDs as the same. By @liuweifeng in #1982
• collapseGroups, check styles as well as attributes. By @johnkenny54 in #1952
• collapseGroups, move attributes atomically. By @johnkenny54 in #1930
• convertPathData, fix q control point when item is removed. By @KTibow in #1927
• convertPathData, preserve vertex for markers only paths. By @SethFalco in #1967
• mergePaths, don't merge paths if attributes/styles depend on the node's bounding box. By @johnkenny54 in #1964
• moveElemsAttrsToGroups, no longer moves the transforms if group has the filter attribute. By @johnkenny54 in #1933
• prefixIds, fixed issue where some IDs were not prefixed when style tag contained XML comments. By @john-neptune in #1942
• removeHiddenElems, don't remove node if child element has a referenced ID. By @johnkenny54 in #1925
• removeHiddenElems, treat path[opacity=0] as a non-rendering node. By @johnkenny54 in #1948
• removeUselessDefs, don't remove node if child element has an ID. By @johnkenny54 in #1923
• When stringifying path data, include a space before numbers represented in scientific notation. By @johnkenny54 in #1961
• No longer crashes when the output (-o argument) ends with a trailing slash to a location that didn't exist. By @SethFalco in #1954

Features

• Add VERSION export so get the version of SVGO during runtime. By @SethFalco in #2016
• Introduce an isPreset and plugins property to plugins, which are only defined for presets. This will indicate if the plugin is a preset, and return the plugins that in the preset in the order they are invoked.

SVG Optimization

• convertColors, introduce parameter to convert colors to common casing (lowercase/uppercase). By @JayLeininger in #1692
• removeDeprecatedAttrs, new plugin that is disabled by default to remove SVG attributes that are deprecated. By @jdufresne in #1869

Metrics

Before and after using vectors from various sources, with the default preset of each respective version:

SVG	Original	v3.3.2	v4.0.0-rc.0	Delta
Arch Linux Logo	9.529 KiB	4.115 KiB	4.097 KiB	⬇️ 0.018 KiB
Blobs	50.45 KiB	42.623 KiB	42.633 KiB	⬆️ 0.01 KiB
Isometric Madness	869.034 KiB	540.582 KiB	540.141 KiB	⬇️ 0.441 KiB
tldr-pages Banner	2.071 KiB	1.07 KiB	1.07 KiB
Wikipedia Logo	161.551 KiB	111.668 KiB	111.727 KiB	⬆️ 0.059 KiB

Note: The increase in size from previous versions is from disabling removeViewBox and removeTitle, with the benefit of preserving scalability and accessibility.

Before and after of the browser bundle of each respective version:

	v3.3.2	v4.0.0-rc.0	Delta
svgo.browser.js	753.0 kB	754.9 kB	⬆️ 1.9 kB

v3.3.2

Notice

An update on what happened with v3.3.0 and v3.3.1. While we have retained CJS support, the migration to ESM has changed the acceptable ways to import SVGO, in ways that users depended on before. This effectively made SVGO v3 a breaking change.

Rather than resolve or workaround these differences, we've opted to release SVGO v3.3.2, which is effectively a revert to v3.2.0, and deprecate versions v3.3.0 and v3.3.1. We'll then proceed to work on releasing v4 which will document the breaking changes, and feature further breaking changes that were slated for v4, like disabling removeViewBox by default.

Before the v4.0.0 release, I'll put more focus on testing and use release candidates, just to make the release go smoothly! 👍🏽

Sorry for the headache, and thanks for your patience.

v3.3.1

Notice

SVGO v3.3.0, which was meant to migrate to ESM without breaking CJS support, unfortunately broke CJS projects. There was a mistake with exports, so the loadConfig function wasn't available in the CJS bundle and lead to issues for many users.

Thanks to everyone who raised the issue, and to @nuintun who submitted a pull request to resolve it so quickly.

I apologize for letting that breaking change through, and will aim to do better. Namely, by adding more tests to cover our exports, and any other public interface in general for each distribution of SVGO, so this doesn't happen again.

SVGO v3.3.1 should resolve the issue for CJS projects, but if you encounter anything else, do let us know by opening an issue on GitHub.

v3.3.0

Deprecated

This release introduced breaking changes, which have been reverted in v3.3.2. The bug fixes will be reintroduced in v4.0.0.

What's Changed

ESM

SVGO is now a dual package, serving for both Common JS and ESM usage. We believe there shouldn't be any problems, especially as SVGO as largely stateless, but feel free to open an issue if you encounter problems with this.

To be explicit, this is not a breaking change, and SVGO should continue to work in Common JS projects!

Thanks to @jdufresne for doing the bulk of the work.

Default Behavior

• convertColors, now converts all references to colors excluding references to IDs to lowercase. This can be disabled by setting convertCase to false.

Bug Fixes

• cleanupIds, treat both URI encoded and non-URI encoded IDs as the same. By @liuweifeng in #1982
• collapseGroups, check styles as well as attributes. By @johnkenny54 in #1952
• collapseGroups, move attributes atomically. By @johnkenny54 in #1930
• convertPathData, fix q control point when item is removed. By @KTibow in #1927
• convertPathData, preserve vertex for markers only paths. By @SethFalco in #1967
• mergePaths, don't merge paths if attributes/styles depend on the node's bounding box. By @johnkenny54 in #1964
• moveElemsAttrsToGroups, no longer moves the transforms if group has the filter attribute. By @johnkenny54 in #1933
• prefixIds, fixed issue where some IDs were not prefixed when style tag contained XML comments. By @john-neptune in #1942
• removeHiddenElems, don't remove node if child element has a referenced ID. By @johnkenny54 in #1925
• removeHiddenElems, treat path[opacity=0] as a non-rendering node. By @johnkenny54 in #1948
• removeUselessDefs, don't remove node if child element has an ID. By @johnkenny54 in #1923
• When stringifying path data, include a space before numbers represented in scientific notation. By @johnkenny54 in #1961
• No longer crashes when the output (-o argument) ends with a trailing slash to a location that didn't exist. By @SethFalco in #1954

SVG Optimization

• convertColors, introduce parameter to convert colors to common casing (lowercase/uppercase). By @JayLeininger in #1692
• removeDeprecatedAttrs, new plugin that is disabled by default to remove SVG attributes that are deprecated. By @jdufresne in #1869

Metrics

Before and after using vectors from various sources, with the default preset of each respective version:

SVG	Original	v3.2.0	v3.3.0	Delta
Arch Linux Logo	9.529 KiB	4.115 KiB	4.097 KiB	⬇️ 0.018 KiB
Blobs	50.45 KiB	42.623 KiB	42.609 KiB	⬇️ 0.014 KiB
Isometric Madness	869.034 KiB	540.582 KiB	540.073 KiB	⬇️ 0.509 KiB
tldr-pages Banner	2.071 KiB	1.07 KiB	1.07 KiB
Wikipedia Logo	161.551 KiB	111.668 KiB	111.668 KiB

Before and after of the browser bundle of each respective version:

	v3.2.0	v3.3.0	Delta
svgo.browser.js	910.9 kB	753.0 kB	⬇️ 157.9 kB

v3.2.0

What's Changed

Bug Fixes

• convertPathData, fix instances were q was incorrectly converted to t. By @KTibow in #1889
• convertTransform, fix for some transforms that weren't being converted correctly. By @SethFalco in #1916

SVG Optimization

• convertPathData, improves closing paths and how we determine if to use absolute or relative commands. By @KTibow in #1867
• convertPathData, round arc or convert to lines based on the sagitta, can be disabled by setting smartArcRounding to false. By @KTibow in #1873
• convertPathData, convert cubic Bézier curves to quadratic Bézier curves where possible, can be disabled by setting convertToQ to false. By @KTibow in #1889

Performance

• mergePaths, refactor for performance with large files. By @mozzie in #1764 and #1904
• convertPathData, refactor #stringifyPathData for performance. By @SethFalco in #1900
• Use Set instead of Array for faster lookups. By @SethFalco in #1899

Metrics

Before and after using vectors from various sources, with the default preset of each respective version:

SVG	Original	v3.1.0	v3.2.0	Delta
Arch Linux Logo	9.529 KiB	4.162 KiB	4.115 KiB	⬇️ 0.047 KiB
Blobs	50.45 KiB	42.949 KiB	42.623 KiB	⬇️ 0.326 KiB
Isometric Madness	869.034 KiB	550.153 KiB	540.582 KiB	⬇️ 9.571 KiB
tldr-pages Banner	2.071 KiB	1.07 KiB	1.07 KiB
Wikipedia Logo	161.551 KiB	116 KiB	111.668 KiB	⬇️ 4.332 KiB

Before and after of the browser bundle of each respective version:

	v3.1.0	v3.2.0	Delta
svgo.browser.js	660.9 kB	910.9 kB	⬆️ 250 kB

v3.1.0

What's Changed

Bug Fixes

• prefixIds, correctly prefix IDs when <style> tag contains XML comments. By @john-neptune in #1736
• removeHiddenElems, improve handling of definitions (<defs>), namely when <defs> are defined at the end of the document. By @KTibow in #1879
• cleanupEnableBackground, clean up inline-styles too. By @SethFalco in #1866
• cleanupIds, handle URI encoded references properly. By @SethFalco in #1880
• inlineStyles, no longer crashes on non-inlined selectors with a pseudo-class. By @SethFalco in #1865
• Improve handling of URL references in reference attributes (url('#a')) across various plugins. By @SethFalco in #1881

SVG Optimization

• removeUnknownsAndDefaults, now removes defaults in XML declarations too, enabled by default and can be toggled with defaultMarkupDeclarations. By @SethFalco in #1872

Metrics

Before and after using vectors from various sources, with the default preset of each respective version:

SVG	Original	v3.0.5	v3.1.0	Delta
Arch Linux Logo	9.529 KiB	4.608 KiB	4.162 KiB	⬇️ 0.446 KiB
Blobs	50.45 KiB	42.949 KiB	42.949 KiB
Isometric Madness	869.034 KiB	550.153 KiB	550.153 KiB
tldr-pages Banner	2.071 KiB	1.07 KiB	1.07 KiB
Wikipedia Logo	161.551 KiB	117.146 KiB	116 KiB	⬇️ 1.146 KiB

Before and after of the browser bundle of each respective version:

	v3.0.5	v3.1.0	Delta
svgo.browser.js	657.5 kB	660.9 kB	⬆️ 3.4 kB

v3.0.5

What's Changed

Bug Fixes

• cleanupIds, correctly handle references to other nodes in animations. By @KTibow in #1862
• convertPathData, fix issue when removing redundant Z between mergable M/m commands. By @KTibow in #1856
• convertPathData, adhere to error/precision in z conversions. By @KTibow in #1842
• removeEmptyContainers, skip if parent node is <switch>, as empty containers can be used for attributes like requiredFeatures. By @vincentbernat in #1747
• removeHiddenElems, when removing a hidden definition, also remove nodes that reference it. By @SethFalco in #1852
• Output the optimization stats (profit) in red if the file size increased. By @gimler in #1162
• Type definition files now correctly use the .d.ts file extension instead of .ts. By @Exotelis in #1780

Chores

• Improved exported types for the #loadConfig method. By @nuintun in #1844

Metrics

Before and after using vectors from various sources, with the default preset of each respective version:

SVG	Original	v3.0.4	v3.0.5	Delta
Arch Linux Logo	9.529 KiB	4.735 KiB	4.608 KiB	⬇️ 0.127 KiB
Blobs	50.45 KiB	42.949 KiB	42.949 KiB
Isometric Madness	869.034 KiB	550.593 KiB	550.153 KiB	⬇️ 0.44 KiB
tldr-pages Banner	2.071 KiB	1.07 KiB	1.07 KiB
Wikipedia Logo	161.551 KiB	117.152 KiB	117.146 KiB	⬇️ 0.006 KiB

Before and after of the browser bundle of each respective version:

	v3.0.4	v3.0.5	Delta
svgo.browser.js	656.9 kB	657.5 kB	⬆️ 0.6 kB

v3.0.4

Includes various bug fixes for existing plugins and a new optimization. Also splits removeXMLNS, which removed XLink, into two separate plugins, removeXMLNS and removeXlink.

What's Changed

Default Behavior

• removeXMLNS, no longer removes the XLink (xmlns:xlink) namespace. If that is desirable, you should enable the new removeXlink plugin, which does more while being safer. By @TrySound and @SethFalco in #1535

Bug Fixes

• convertPathData, ignore instances where transform applied via style tag. By @SethFalco in #1830
• inlineStyles, inline properties with the same specificity in the order that they appear in the stylesheet. By @SethFalco in #1831
• inlineStyles, don't remove class or id from node if it's traversed in another CSS selector. By @SethFalco in #1832 and #1836
• Don't trim pre elements in foreignObject. By @SethFalco in #1796
• Don't crash when encountering @-webkit-keyframes in <style> node. By @SethFalco in #1826

SVG Optimization

• convertPathData, convert to z command if going back to initial position, or drop z if redundant. By @KTibow in #1822
• inlineStyles, when inlining a CSS property that's already declared in a presentation attribute of the node, drop the attribute. By @SethFalco in #1829
• removeXlink, new plugin that removes the XLink (xmlns:xlink) namespace and migrates from XLink attributes to the SVG 2 equivalent. Disabled by default. By @TrySound and @SethFalco in #1535

Metrics

Before and after using vectors from various sources, with the default preset of each respective version:

SVG	Original	v3.0.3	v3.0.4	Delta
Arch Linux Logo	9.529 KiB	4.738 KiB	4.735 KiB	⬇️ 0.003 KiB
Blobs	50.45 KiB	42.949 KiB	42.949 KiB
Isometric Madness	869.034 KiB	550.699 KiB	550.593 KiB	⬇️ 0.106 KiB
tldr-pages Banner	2.071 KiB	1.07 KiB	1.07 KiB
Wikipedia Logo	161.552 KiB	118.441 KiB	117.152 KiB	⬇️ 1.289 KiB

Before and after of the browser bundle of each respective version:

	v3.0.3	v3.0.4	Delta
svgo.browser.js	651.7 kB	656.9 kB	⬆️ 5.2 kB

v3.0.3

Includes various bug fixes and optimizations for existing plugins.

We're also revamped the documentation for the project. You can find it on svgo.dev!
The frontend for svgo.dev is maintained in svg/svgo.dev, contributions are welcome.

What's Changed

Default Behavior

• removeComments, introduces preservePatterns parameter. Preserves legal comments by default, same as the previous behavior, but can now be overridden. By @SethFalco in #1812
• removeDesc, set the removeAny parameter to false by default for accessibility. By @SethFalco in #1806

Bug Fixes

• removeRasterImages, removes inline JPEG images. By @abejfehr in #1742
• cleanupIds, correctly handle when 2 IDs have been referenced in a single attribute. By @SethFalco in #1795
• cleanupIds, correctly handle when we've encountered a reference to a node that doesn't exist. By @SethFalco in #1817
• inlineStyles, treat style prop keys as case-insensitive. By @SethFalco in #1797
• inlineStyles, remove all classes in multiclass selector. By @SethFalco in #1801
• inlineStyles, ignore empty CSS blocks instead of adding empty style attribute. By @SethFalco in #1823
• minifyStyles, removes unused class selectors when the document has no classes. By @SethFalco in #1800
• prefixIds, reuse the same prefix when encountering an ID multiple times. By @SethFalco in #1814
• removeHiddenElems, stops removing non-rendering elements like masks. By @SethFalco in #1793
• reusePaths, creates a new ID if the current one is referenced by another element. By @SethFalco in #1784
• reusePaths, removes redundant defs children after optimization. By @SethFalco in #1785
• reusePaths, stops duplicating attributes into the shared definition. By @SethFalco in #1791
• Don't crash on a null, undefined, or empty plugin. Instead, log a warning and ignore it. By @SethFalco in #1128

SVG Optimization

• convertTransform, omit spaces between functions. By @SethFalco in #1802
• removeScriptElement, removes callbacks (on*) and href attributes with javascript: URIs. By @cakeinpanic and @SethFalco in #1807, #1818, #1819, #1820
• convertOneStopGradients, new plugin to convert gradients with one stop to a solid color, disabled by default. By @SethFalco in #1790

Performance

• Various optimizations for path handling. By @marvinhagemeister in #1716 and #1717

Chores

• Revise the README. By @ADTC in #1731
• Fix dead link to postcss-svgo in README. By @Lehoczky in #1770
• Replace webpack loader library in README as previous was deprecated. By @tanyabouman in #1771

Metrics

Before and after using vectors from various sources, with the default preset of each respective version:

SVG	Original	v3.0.2	v3.0.3	Delta
Arch Linux Logo	8.584 KiB	4.748 KiB	4.747 KiB	⬇️ 0.001 KiB
Blobs	50.45 KiB	42.949 KiB	42.949 KiB
Isometric Madness	869.034 KiB	550.829 KiB	550.699 KiB	⬇️ 0.13 KiB
tldr-pages Banner	2.071 KiB	1.07 KiB	1.07 KiB
Wikipedia Logo	161.552 KiB	118.441 KiB	118.441 KiB

Before and after of the browser bundle of each respective version:

	v3.0.2	v3.0.3	Delta
svgo.browser.js	643.5 kB	651.7 kB	⬆️ 8.2 kB