Drop
Add up to five PNG or JPEG files. Preflint reads actual file signatures, not just extensions.
Built for App Store assets
Check App Store assets before upload.
Validate screenshots, promotional images, and icons directly in your browser. Find technical problems, apply safe fixes, and export corrected copies.
No upload · Works in your browser · Files stay local
iphone-hero.png1290 × 2796
paywall.jpg1170 × 2532
iap-offer.png1024 × 1024
Plan smarter.
RESULTS1 issue found
DimensionsExpected 1290 × 2796
TransparencyAll pixels opaque
Manual reviewConfirm app content
From source file to checked export.
Clear, local steps without an account, upload queue, or hidden server.
Analyze
Review dimensions, encoding, transparency, color markers, density metadata, and target-specific results.
Fix
Preview re-export, conversion, flattening, padding, or crop operations before creating a copy.
Export
Download one corrected file or a structured ZIP after every output is reopened and checked again.
Drop PNG or JPEGActual bytes stay on this device
Encoding confirmed
Resize needs review
Output reinspected
Preflint for Mac
A native workflow for production batches.
Use the free browser app for quick checks. Move to the native Mac app when you need folders, larger batches, Finder integration, deeper metadata visibility, and richer reports.
- Scan folders and organize larger batches
- Faster processing for large source files
- Advanced ICC and ColorSync inspection
- Detailed export reports and native shortcuts
$24.99 · One-time purchase · Coming soon
iphone-hero.png1290 × 2796
paywall.jpg1170 × 2532
iap-offer.png1024 × 1024
Plan smarter.
RESULTS1 issue found
DimensionsExpected 1290 × 2796
TransparencyAll pixels opaque
Manual reviewConfirm app content
Choose the workflow that fits the batch.
Both products share deterministic rules. Browser capabilities remain intentionally honest.
| Feature | Web | Mac |
|---|---|---|
| Basic validation | Yes | Yes |
| PNG/JPEG conversion | Yes | Yes |
| Transparency flattening | Yes | Yes |
| Up to 5 files per batch | Yes | — |
| Folder scanning | — | Yes |
| Large batch workflows | — | Yes |
| Advanced ICC inspection | Limited | Yes |
| Finder integration | — | Yes |
| Detailed reports | Basic | Yes |
Preflint Web
Open Web AppFree
Use directly in your browser
Preflint for Mac
Mac app — Coming soon$24.99
One-time purchase
FAQ
Clear answers before you add a file.
Preflint is careful about what a browser can—and cannot—prove.
Are my images uploaded?+
No. Files are processed locally in your browser and are never uploaded.
Is Preflint affiliated with Apple?+
No. Preflint is an independent developer utility and is not affiliated with or certified by Apple.
Does it guarantee approval?+
No. Preflint finds deterministic technical file issues. App Review includes policies and judgment that software cannot guarantee.
What works in the browser?+
PNG/JPEG inspection, target dimensions, transparency scanning, format conversion, flattening, crop or padding resize, metadata-removing re-export, and ZIP download.
Why use the Mac app?+
The native app is designed for folders, larger batches, Finder workflows, faster large-file processing, richer reports, and more reliable ICC/ColorSync inspection.
Which file types are supported?+
The browser MVP accepts PNG and JPEG files up to 40 MB, with up to five files in a batch.
Does Preflint use AI?+
No. Every check is deterministic and rule-based.
Can it check App Store icons completely?+
No. A single image cannot prove every icon rendition and visual policy requirement. Preflint provides basic source-image checks and clear manual reminders.