Actual encoding detection
PNG and JPEG signatures are checked from file bytes. Extension mismatches are reported.
A real asset checker, built into the browser.
Preflint inspects source bytes, decodes pixels when necessary, creates corrected copies, and reopens outputs before export.
Deterministic inspection
Dimensions, PNG chunks, JPEG markers, density metadata, color indicators, and alpha capability are parsed locally.
Transparent-pixel scan
Potential alpha is separated from confirmed transparent pixels using decoded pixel data.
Visible corrections
Convert, flatten, fit with padding, fill with crop, and metadata-removing re-export with an updated preview.
Checked ZIP exports
Batch output includes Ready and Needs Manual Review folders plus a JSON report without image bytes or local paths.
Private file lifecycle
No uploads, persistence, analytics, telemetry, accounts, or third-party processing.
Privacy-first by architecture
Privacy detailsFiles are processed locally in your browser and are never uploaded.
User images live only in temporary browser memory and object URLs. Clearing a batch revokes those URLs and releases the processing state.
Deterministic in the browser
- Magic-byte encoding
- PNG and JPEG metadata
- Dimensions and orientation
- Actual transparent pixels
- Target rule matching
- Output reinspection
Explicitly manual
- Visual policy compliance
- Content accuracy
- Trademark and copyright
- Readability
- Rounded-corner appearance
- App Review decisions