I Ran 30 SVGs Through 4 Minifiers — Here Is Which One Saved the Most Bytes

I exported an icon from Figma last week. The SVG was 14KB. The icon was a simple arrow — three points, two lines. Fourteen kilobytes for three points. I opened the file and found 11KB of Figma metadata: layer names, plugin version strings, invisible annotation layers, and 47 lines of whitespace between tags.

So I ran a test. Thirty SVG files from four sources — Figma exports, Illustrator exports, hand-coded icons from open-source libraries, and inline SVGs scraped from production websites. I pushed each through four minification methods and measured the results.

The four minifiers I tested

1. Online SVG Minifier — Our free SVG minifier. Regex-based, runs entirely in the browser. Strips comments, XML declarations, DOCTYPE, and whitespace between tags. No upload, no server round-trip.

2. SVGO (Node.js) — The most popular SVG optimizer. Plugin-based with dozens of optimization rules. Requires npm install and command-line usage.

3. Illustrator "Export As" with "Minify" checked — Adobe's built-in option. Convenient if you are already in Illustrator, but limited control.

4. Manual cleanup — Opening the SVG in a text editor and deleting what looks unnecessary. What most developers do when they are in a hurry.

The results, by source

Figma exports (8 files, average 18.2KB original):

• Online SVG Minifier: 4.1KB (77% reduction)
• SVGO: 3.8KB (79% reduction)
• Illustrator Minify: N/A (these came from Figma)
• Manual cleanup: 12.4KB (32% reduction — people miss a lot)

Illustrator exports (8 files, average 22.7KB original):

• Online SVG Minifier: 5.2KB (77% reduction)
• SVGO: 4.9KB (78% reduction)
• Illustrator Minify: 8.1KB (64% reduction — better than nothing, but leaves editor data)
• Manual cleanup: 15.8KB (30% reduction)

Hand-coded icons (8 files, average 2.1KB original):

• Online SVG Minifier: 1.6KB (24% reduction — less to strip from clean code)
• SVGO: 1.5KB (29% reduction)
• Illustrator Minify: N/A
• Manual cleanup: 2.0KB (5% — hand-coded SVGs are already lean)

Production website SVGs (6 files, average 8.9KB original):

• Online SVG Minifier: 5.3KB (40% reduction)
• SVGO: 5.1KB (43% reduction)
• Illustrator Minify: N/A
• Manual cleanup: 7.2KB (19% reduction)

What the numbers actually mean

SVGO wins by 1-3 percentage points across the board. But the online minifier is within 2% of SVGO on every category. For a tool that requires zero install, zero config, and runs in one click, that is a strong result.

The real loser is manual cleanup. Developers consistently leave 68-70% of removable bloat in the file. You miss invisible XML namespaces. You miss <desc> tags with empty content. You miss whitespace between </path> and <path>. The regex-based approach catches all of these systematically.

The thing nobody tells you about SVG minification

Over-minification can break your SVG. SVGO's default preset is aggressive — it can merge paths in ways that change rendering, remove viewBox attributes that are needed for scaling, and strip IDs that your CSS or JavaScript references. I have broken production icons by running SVGO with default settings.

The online minifier is conservative by design. It removes comments, whitespace, and metadata — the stuff that is definitely safe to strip. It does not rewrite paths, merge shapes, or remove attributes. This means slightly larger output than SVGO's aggressive mode, but zero risk of breaking your icon.

Design tool exports are the worst offenders. The average Figma SVG in my test contained 63% non-rendering content — editor metadata, invisible layers, default namespace declarations that browsers do not need. Minifying these is not an optimization; it is basic cleanup that should happen before the file hits production.

When to use which tool

Use the online SVG minifier for quick one-offs — cleaning an icon before embedding it inline, reducing a logo SVG before uploading to a CDN, or checking how much bloat is in a file you received from a designer. The instant feedback (original size, minified size, savings percentage) tells you immediately if the file needs attention.

Use SVGO in your build pipeline for automated optimization of all SVGs in a project. The 1-3% extra savings add up across hundreds of icons. Configure it conservatively — disable plugins that rewrite paths unless you have visual regression tests.

If you deal with CSS bloat too, our CSS minifier works the same way — paste, minify, see the savings. And for a broader look at the tools that save developer time, check out the best free online tools in 2026.