Image auto contrast
Stretch each RGB channel’s sampled minimum and maximum across its full range. Your inputs stay in this browser tab.
Your result
A little input. A useful result.
Your result will appear here.How to use image auto contrast
Stretch each RGB channel’s sampled minimum and maximum across its full range. This free tool runs locally after you choose to start.
- Choose supported files from your device.
- Check your selection before continuing.
- Choose the action button. Review the result, then copy text or download a file when available.
- Choose Clear all when finished to remove inputs and results from the interface.
Limits, without the small print.
PNG, JPEG or WebP only. Maximum 20 MB and 12 megapixels. Output is re-encoded. Keep the original; this does not remove visible personal information. May shift color balance. Fully transparent pixels are excluded from bounds.
One job runs at a time. You can cancel it; jobs stop after 30 seconds. Browser and device capabilities affect performance.
Understand the safeguards →What this tool does
Stretch each RGB channel’s sampled minimum and maximum across its full range.
Example input
Select a supported local file; the visible settings are a starting example.
What to expect
Review the generated local preview or downloadable copy before using it.
A couple of useful answers.
Does image auto contrast upload my data?
No. This tool processes your input in a browser worker. Your text and files are not sent to an application server. The static host receives page and asset requests; see our privacy explanation.
Is this tool free for work and study?
Yes. No account, paid API, usage subscription or watermark fee is required. You remain responsible for your content rights and checking results. Hosting providers and their free tiers are separate from this open-source software.
What should I check before relying on the result?
PNG, JPEG or WebP only. Maximum 20 MB and 12 megapixels. Output is re-encoded. Keep the original; this does not remove visible personal information. May shift color balance. Fully transparent pixels are excluded from bounds. Review important outputs against the source, especially financial, legal, identity, medical and research calculations.