SVGN vs. SVGO: A Comparison

svgn is a native Rust port of svgo, the popular JavaScript-based SVG optimizer. While svgn aims for functional parity and API compatibility with svgo, there are fundamental differences stemming from their underlying technologies (Rust vs. JavaScript) that impact performance, deployment, and ecosystem integration.

Key Differences

Feature	SVGN (Rust)	SVGO (JavaScript)
Language	Rust	JavaScript (Node.js)
Performance	Generally faster due to Rust’s native execution and memory management. Ideal for CPU-bound tasks.	Good performance, but limited by JavaScript runtime overhead.
Memory Usage	Lower memory footprint due to Rust’s ownership model and lack of garbage collector.	Higher memory usage due to JavaScript’s garbage collection and runtime.
Ecosystem	Integrates seamlessly with Rust projects and the Cargo ecosystem.	Integrates with Node.js projects and the npm/Yarn ecosystem.
Deployment	Compiles to native executables, WebAssembly (WASM), or can be used as a library.	Requires Node.js runtime for execution. Browser usage requires bundling.
Concurrency	Leverages Rust’s strong concurrency primitives for potential parallel processing of SVG optimization tasks.	Primarily single-threaded, though asynchronous operations are common.
Error Handling	Rust’s robust type system and Result/Option enums enforce explicit error handling at compile time.	Relies on exceptions and runtime error handling.
Binary Size	Native executables can be larger due to static linking, but WASM output can be compact.	Smaller package size, but requires Node.js runtime.
Use Cases	High-performance backend services, desktop applications, CLI tools, WASM in browsers.	Web development workflows, build tools, Node.js applications, browser-based optimization (with bundling).
CLI Compatibility	Full drop-in replacement for SVGO CLI with identical syntax and behavior.	Original implementation.
Plugin Support	46/53 plugins implemented (87% coverage), 1 disabled due to CSS parsing.	All 53 plugins available.

Functional Parity

svgn has achieved substantial functional parity with svgo v4.0.0:

• Plugin Coverage: 46 out of 53 plugins (87%) have been successfully ported, including all commonly used optimization plugins.
• CLI Compatibility: Full command-line compatibility achieved - svgn can be used as a drop-in replacement for svgo CLI.
• Test Coverage: 359 tests passing (100% success rate), including SVGO compatibility tests achieving 93.75% parity.
• Configuration Mapping: svgn’s configuration structure (SvgnConfig) directly maps to svgo’s configuration object.

Current Implementation Status

Implemented (46 plugins):

• All basic optimization plugins (removeComments, removeDoctype, etc.)
• Numeric and value cleaners (cleanupNumericValues, cleanupListOfValues)
• Attribute processors (sortAttrs, removeAttrs, cleanupAttrs)
• Style handlers (convertColors, convertStyleToAttrs, minifyStyles)
• Structural optimizers (collapseGroups, removeHiddenElems)
• Security plugins (removeScripts, removeRasterImages)
• Transform handlers (removeUselessTransforms)

Not Yet Implemented (7 plugins):

• applyTransforms (applies transforms to coordinates)
• convertTransform (transform matrix optimization)
• inlineStyles (CSS inlining)
• mergePaths (path merging)
• moveElemsAttrsToGroup/moveGroupAttrsToElems (attribute movement)
• removeUselessStrokeAndFill (style cascade analysis)
• reusePaths (path deduplication)

When to Choose SVGN?

Consider using svgn if:

• You require maximum performance for SVG optimization, especially for large batches of files or in performance-critical environments.
• You are working within a Rust ecosystem and prefer a native solution without Node.js dependencies.
• You plan to deploy SVG optimization to WebAssembly (WASM) for client-side or edge computing scenarios.
• You value strong type safety and compile-time error checking.
• You need a drop-in CLI replacement for SVGO with enhanced features like better STDIN/STDOUT handling.
• • The 48 currently implemented plugins cover your optimization needs.

When to Choose SVGO?

svgo remains an excellent choice if:

• You are already heavily invested in the Node.js/JavaScript ecosystem.
• Your performance requirements are met by svgo’s current capabilities.
• You require one of the 3 plugins not yet implemented in svgn.
• You need immediate access to the latest svgo features and plugins as they are released.
• You prefer the flexibility and rapid development cycles often associated with JavaScript.

Ultimately, the choice between svgn and svgo depends on your specific project requirements, performance needs, and technology stack preferences.