Reference
How FixMySVG analyzes and repairs SVG files
By FixMySVG · Published Oct 4, 2026 · 6 min read
This page explains what happens when you drop an SVG into FixMySVG: what is measured, where each rule comes from, how a repair is checked so it doesn’t change the design, and when a file needs your hands instead.
On this page
1. Reading the file
The file is parsed as XML in your browser, inside a Web Worker. Before anything is displayed, scripts, event handlers and references to outside resources are removed, because an SVG is treated as untrusted. Previews are shown as images, never inserted into the page.
Then the structure is measured. FixMySVG counts paths and shapes, path commands (an approximation of nodes), elements, groups and how deeply they nest, and records editable text, embedded and linked images, clipping paths, masks, patterns, gradients, filters, <use> copies, hidden, invisible and off-canvas objects, duplicate IDs, the viewBox and the declared size. More than 30 checks are computed from these measurements.
FixMySVG guidance
Paths, as FixMySVG counts them: every shape in the artwork, including hidden and invisible ones, which means <path> elements, basic shapes (rectangles, circles, polygons and so on) and the copies created by <use>. Shapes kept only as definitions (inside <defs>, <symbol>, clipping paths or masks) count only when a <use> element draws them. Cricut doesn’t define what counts as a path, and Design Space turns basic shapes into paths.
2. Where each rule comes from
- Cricut documented requirements come from two Cricut help articles: the 5,000-path limit (How to upload images into Design Space) and the unsupported items, meaning pattern fills, clipping paths, editable text, linked images and embedded non-vector images (Image uploads: unsupported items).
- FixMySVG compatibility warnings are FixMySVG’s own: hidden or off-canvas objects, outline-only shapes,
<use>copies, filters, a very high node count, tiny pieces, a missingviewBoxand a path count within 10% of the limit, among others. - General SVG best practice comes from the SVG and CSS specifications.
In the Cricut section of the report, every finding is marked as a Cricut documented requirement (linked to the help article it comes from), a FixMySVG compatibility check or general SVG best practice. The Cricut SVG requirements page lists all three groups side by side.
3. The verdict
| Verdict | Meaning |
|---|---|
| Not ready | At least one problem: a documented Cricut restriction (more than 5,000 paths, editable text, clipping paths, masks, pattern fills, embedded or linked images), content a cutting app can’t use (<foreignObject>), or a file that can’t be read reliably (broken XML, an invalid viewBox, a missing SVG namespace or nothing visible). |
| Needs attention | No blocking problem, but warnings that commonly cause wrong uploads, such as gradients, hidden objects, outline-only shapes or a missing viewBox. |
| Ready | No known problem was found. |
Watch out
FixMySVG doesn’t run Cricut Design Space. The verdict comes from Cricut’s published rules and from the structure of the file, not from an actual upload, and Cricut doesn’t publish every detail of how Design Space imports SVGs.
4. How Safe Fix checks every repair
Safe Fix applies its repairs in groups (cleanup, hidden objects, IDs, styles, precision and so on). The original and the repaired file are rendered with resvg, an SVG renderer compiled to WebAssembly that runs in your browser, and their pixels are compared. For files with up to 40,000 elements this happens after every group; larger files are compared once, when all repairs are done.
- Render size: 512 pixels on the longest side for each group, then a final check of the finished file at 1,024 pixels. Files with more than 40,000 elements get only the final check, at 768 pixels; if it fails, Safe Fix starts again with only its most conservative repairs (cleanup, empty groups and duplicate IDs) and checks again.
- What counts as a changed pixel: each pixel is composited over white and over black, and it counts as changed when a color channel moves by more than 32 out of 255. Smaller differences are anti-aliasing noise.
- When a repair is kept: only if the result is identical or the change is negligible (at most 4 changed pixels, or 0.05% of the drawn pixels on large designs). Otherwise the group is undone and the report says so. If the final check still finds a difference, the report shows a visible change instead of calling the file safe.
- Text: the renderer draws no fonts, so text is protected separately: no repair edits text, and once all repairs are done, the text in the result is compared with the original.
- Very large files: above 200,000 elements the file can’t be rendered reliably for comparison, so the result is marked as unverified instead of safe.
Deeper optimization on paid plans (applying transforms and combining same-color shapes that don’t overlap) goes through the same verification.
5. Before and after
After a repair you see the original next to the repaired file, along with the numbers that changed: paths, commands, file size and the Cricut verdict. On paid plans a detailed comparison adds a slider and a difference map that highlights any changed pixels.
6. When a file needs manual action
What FixMySVG can and can’t do
- Automatically fixableHidden, invisible and off-canvas objects, editor data, metadata, unused definitions, empty groups, duplicate IDs, inline styles, unsafe content, HTML entities that break the XML, and a missing or invalid
viewBox(when width and height are known). - May be safely optimizedFewer paths by combining same-color shapes that don’t overlap (Creator and Pro), verified pixel by pixel. It can’t always get a file under 5,000 paths.
- Manual action recommendedEditable text, clipping paths and masks, pattern fills and gradients, embedded or linked images, strokes that should cut as shapes, simplifying nodes and splitting a design. The report explains how in each case.
- Can’t be reliably repaired automaticallyConverting text without the original font, turning a photo into faithful cut shapes, or deciding which details of a design to delete.
FixMySVG never converts text automatically: without the exact font installed, the lettering would change. The guide to SVG text that doesn’t work in Cricut shows how to do it in Illustrator, Inkscape and Affinity Designer.
7. How the engine itself is tested
An automated test suite covers parsing, path counting, the Cricut rules, sanitization and Safe Fix, and runs before every release.
FixMySVG guidance
FixMySVG testing, October 2026: the engine was run on 985 SVG files, namely 348 from the resvg test suite, 390 SVGO test files, 137 Scour test files, 100 Twemoji icons and 10 FixMySVG sample files. 21 of them couldn’t be read (16 contained malformed XML and 5 weren’t SVG files), and the checker reported that instead of a verdict. Safe Fix (basic and deeper) ran on the other 964. Every result was rendered again with an independent check at 1,000 pixels, its text compared and the output analyzed again. There were no crashes, no text changes and no visual change that the report didn’t disclose. For 23 files Safe Fix reported that it couldn’t confirm an unchanged look, and those results were shown as unverified rather than safe.
8. What stays private
- Analysis and Safe Fix run in your browser. The file isn’t uploaded to check it, repair it or compare it.
- For Safe Fix, the server only checks your allowance. It receives a few numbers, such as the path count, and the file name (kept only in a signed-in user’s own history), never the file itself.
- When you’re signed in, your dashboard keeps a list of recent files: name, size, path count and result. You can clear it at any time.
- A file is only stored on the server if you explicitly save it as a project.
- Analytics, when enabled, never receive file contents or file names. The Copy report text contains measurements only, not your file name.
See the method on your own file
Each Cricut finding in the report shows where it comes from.
Frequently asked questions
- Does FixMySVG upload my SVG to a server?
- No. Analysis, Safe Fix and the comparison run in your browser. A file is only stored on the server if you explicitly save it as a project in your dashboard.
- Does FixMySVG test files in Cricut Design Space?
- No. It checks files against the rules Cricut documents and against known problem structures. It doesn’t run Design Space or upload anything to Cricut.
- Can Safe Fix change how my design looks?
- Repairs are rendered and compared with the original, and a group of repairs that would change the look is undone. Very large files are compared once at the end, and a file too large to render reliably is marked as unverified, not safe.
- Why are some fixes manual?
- Some repairs need decisions or resources a tool doesn’t have, such as the original font for text, or which details of a design you are willing to lose.
Sources
- Cricut documentationCricut Help: How to upload images into Design Space
- Cricut documentationCricut Help: Image uploads — unsupported items
Related SVG guides
SVG upload problems7 min read
SVG not uploading to Cricut? 9 causes and how to fix each one
Why an SVG won’t upload or looks wrong in Cricut Design Space — path limit, text, clipping paths, hidden objects, bad XML — and how to fix each.
SVG upload problems8 min read
Unsupported items in a Cricut SVG: what each one is and how to fix it
What the Cricut unsupported items message means for your SVG: the five items Cricut lists, the extra checks FixMySVG adds, and how to fix each one.
SVG structure8 min read
How to reduce SVG paths without ruining your design
Practical ways to reduce SVG paths and nodes: combining shapes, Union, removing duplicates and specks, cleaning up traces, simplifying, and what each costs.
SVG appearance problems8 min read
Why your SVG shows a black box in Cricut Design Space
SVG showing a black box or solid shape in Cricut Design Space? See the possible causes, from unfilled shapes and masks to images and CSS, and how to fix each.