Remove unknowns & defaults (removeUnknownsAndDefaults)
Drops attributes and elements that match SVG defaults or are unknown to the spec.
What Remove unknowns & defaults does in SVGO
SVGO applies removeUnknownsAndDefaults as part of its plugin pipeline. On SVGOMG.net the toggle is labeled Remove unknowns & defaults (enabled by default). Optimization runs entirely in your browser — files are not uploaded to a server.
Use SVGOMG.net with Show original to compare before and after. If output looks wrong, disable this plugin first, then re-enable related transforms one at a time.
When to enable
Safe default for shrinking verbose editor output.
When to disable
When targeting non-standard attributes your runtime depends on.
Watch out for
May remove vendor-specific attributes you still need.
Try it
- Open SVGOMG.net and load your SVG (file, paste, or demo).
- Find Remove unknowns & defaults in the Features panel (
removeUnknownsAndDefaults). - Toggle the plugin and compare the preview; download when satisfied.
Part of: Attributes and namespaces
This plugin is covered in the Attributes and namespaces topic guide along with related transforms.
SVGO Plugin Guide
Browse the SVGO Plugin Guide or read the full SVG optimization walkthrough.