SVGO removeDimensions plugin: limits on width/height removal when viewBox present

Answer

The removeDimensions plugin strips the root width and height attributes only when the plugin is active and a valid viewBox is present. If the plugin is disabled or the viewBox is missing/invalid, the attributes are left untouched. You can keep the dimensions by turning the plugin off in your SVGO configuration.

Confirmed facts (SVGO 2.x and 3.x)

• The plugin works on the root <svg> element only. It checks for a parsable viewBox; if present, it removes width and height attributes.
• If viewBox is absent, empty, or malformed, the plugin does not touch those attributes.
• The plugin examines attributes only; CSS‑defined dimensions (via style or external stylesheets) are ignored.
• Nested <svg> elements are processed independently; the plugin does not affect their dimensions.
• The core removal logic is unchanged between SVGO 2.x and 3.x; differences are limited to the configuration format.

Likely explanation (version‑specific config)

• SVGO 2.x: plugins are listed as objects, e.g. { name: 'removeDimensions', active: true }. Setting active: false or omitting the plugin disables stripping.
• SVGO 3.x: the default preset is applied via preset-default. To override, you can use plugins: [{ name: 'preset-default', params: { overrides: { removeDimensions: false } } }] or directly add { name: 'removeDimensions', active: false } to the plugins array.
• Behavior regarding nested SVGs and CSS dimensions is the same across both major versions.

Steps to verify or control the behavior

1. Check your SVGO version: svgo -v.
2. Inspect your configuration (e.g., svgo.config.js or CLI preset).
3. Run a quick test on a minimal SVG:

<svg width="200" height="100" viewBox="0 0 200 100" xmlns="http://www.w3.org/2000/svg">
  <rect width="200" height="100" fill="#fff" />
</svg>

Execute:

svgo test.svg -o test-out.svg

Inspect test-out.svg: if width and height are gone, the plugin is active. To keep them, either:

Disable the plugin via config as shown above, or
Pass --disable=removeDimensions on the command line.

Edge cases where attributes are preserved despite a viewBox

Missing or empty viewBox (e.g., viewBox="" or omitted).
Malformed viewBox that SVGO cannot parse (non‑numeric values).
Plugin explicitly disabled or overridden in the configuration.
Width/height defined only in CSS (e.g., style="width:200px;height:100px") – the plugin does not touch these.

Missing diagnostic detail
If you are using a custom preset or have overridden the removeDimensions plugin elsewhere, the recommendation changes. Please confirm whether your SVGO configuration includes any overrides for this plugin.