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Check what color and structure a 3MF file actually contains.

Inspect a 3MF's objects, colors, materials, textures, transforms, and extensions. You can also compare a color round trip. Everything runs locally and your file is never uploaded.

Processing on your device Evidence, not a score No account required
Meshworthy 3MF Color Inspector Private session · No upload

Drop one file here

Accepted: .3mf up to 100 MiB.

Runs locally in your browser. Your model is not uploaded, stored, or included in analytics. Package metadata is shown only on this device. Review it before sharing screenshots or copied reports.

How it works

From package to evidence in three private steps.

  1. 01
    Open safely

    Your browser checks fixed package limits before reading the 3MF.

  2. 02
    Map the semantics

    Objects, colors, materials, textures, transforms, namespaces, and references are inventoried.

  3. 03
    Review evidence

    See named checks and a preview generated on your device. Nothing is uploaded, stored, or logged.

Checked

What the inspection covers.

  • Package safetyZIP structure, normalized paths, size limits, encryption, and traversal entries.
  • Portable colorBase materials, color groups, textures, coordinates, and triangle assignments.
  • Reference integrityMissing resources, invalid indices, cycles, transforms, and required extensions.

Boundaries

What the result does not claim.

  • Not universal conformanceThe tool checks a documented subset; it is not a complete 3MF validator.
  • Extensions stay explicitProduction and Beam Lattice are identified, not semantically evaluated in v1.
  • Data beats appearanceA rendered match never overrides a semantic mismatch in the package.

Round trip method

See what another app preserved. Do not rely on appearance alone.

The reference file is deterministic and follows published standards. Comparison matches objects by name and by a quantized geometry fingerprint, so an application renumbering resource IDs never reads as loss, while a changed property assignment for a triangle always shows a semantic difference. Semantic restructuring is labelled “Changed representation,” not “Lost,” when equivalent appearance can be demonstrated from supported standard data.

Questions

Useful context before you inspect.

What does the 3MF Color Checker inspect?

It inventories objects, build items, transforms, base materials, color groups, textures, property assignments for individual triangles, namespaces, and internal references. It also reports package safety or integrity problems found within its documented 3MF subset.

Why did my 3MF lose its colors after editing?

Color can disappear when an application exports an edited 3MF using a color representation it does not fully support. It may also omit a color group, texture, or property assignment for individual triangles. This tool identifies the portable color resources that the file contains and shows what the application preserved, changed, or lost during the round trip.

Is my file uploaded?

No. The package is opened, parsed, and inspected entirely in your browser. No model, filename, geometry, or metadata is sent over the network, stored, or included in analytics.

Is this a full 3MF validator?

No. It checks a documented subset that covers core geometry, portable color and materials, textures, transforms, and reference integrity. Unknown namespaces are reported without being deleted or interpreted. The result does not claim universal 3MF conformance.

What is the reference file for?

It is a small 3MF built from published standards. It includes base materials, a color group, color assigned to faces and corners, a texture, and a component assembly. Open it in your slicer, export it again, and compare the result to see how faithfully the application preserves portable color.

Which colors and materials does it read?

It reads base material groups, color groups, texture2d resources, texture coordinate groups, object properties, and property assignments for individual triangles as defined by the 3MF Materials and Properties extension.

Need to edit the file?

Inspect here. Preserve it in Meshworthy.

Editing 3MF files and need the colors and materials to survive? Protect 3MF semantics while editing in Meshworthy for Mac. You can also read the guide on why 3MF color disappears after an edit.