File Doctor
A full health check for your image — format, size, dimensions and transparency — then fix everything in one click.
File Doctor
This tool runs entirely in your browser. Your files never leave your device.
How to use
- 1Drop an image onto the box, or choose a file.
- 2Read the health check — each row shows a check and whether it needs attention.
- 3Click 'Fix Everything' to apply the recommended fixes in one pass.
- 4Compare the before/after size, then download the fixed image.
About this tool
File Doctor runs a quick check on any image — its format, file size, pixel dimensions and whether it uses transparency — and explains in plain language which of those are actually worth fixing, not just a wall of technical numbers. A flat PNG that should be WebP, a photo saved far bigger than any screen will show, or a file that's simply heavier than it needs to be: File Doctor catches these and fixes all of them at once with a single click, choosing a format and size that keeps transparency intact when the image needs it. Nothing about the check or the fix requires uploading the file anywhere — the whole diagnosis and repair happens on your device.
Benefits & use cases
- Understand what's actually wrong with an image file in plain language.
- Fix format, size and dimension issues together in one click.
- Keep transparency intact automatically when the image needs it.
- Skip the guesswork of picking a format, quality and resolution by hand.
Frequently asked questions
What exactly does File Doctor check?
Four things: whether the file format is efficient for this image, whether the file size is larger than needed, whether the pixel dimensions are bigger than most screens need, and whether the image uses transparency.
Will 'Fix Everything' ever make my image worse?
No. It only re-encodes to a more efficient format and/or downscales oversized dimensions — content and transparency (where present) are preserved.
What if no issues are found?
You'll see 'No issues found'. You can still click through to re-optimize if you'd like, but it likely won't shrink the file much further.
Is my image uploaded for the health check?
No. The entire diagnosis and fix run in your browser; the file is never sent to a server.