About Screen Tester
Screen Tester is a small, independent project with one goal: the best free screen tester on the web. Open the page and the tool is ready. No sign-up, no app to install, no pop-ups standing between you and the thing you came for.
What we believe
- The tool comes first. It sits at the top of the home page, fully visible on phones, tablets and desktops.
- Your data stays with you. The test patterns are drawn in your browser. Settings are saved only in your own browser’s local storage.
- Accuracy over gimmicks. Every feature is tested with automated browser tests before it goes live, including edge cases most tools ignore.
- Accessible by default. Large tap targets, keyboard shortcuts, readable contrast and screen-reader labels.
How we build and test
- The test patterns (solid colors, gray fields, gradients, level patches, pixel lines, moving blocks and the stuck pixel fixer) are drawn in your browser at your screen’s own pixel density and checked by automated tests that read back the exact pixel values.
- Refresh rate is measured from how often your browser draws frames, so it reflects what the browser receives and may differ from your monitor’s settings in rare cases.
- The stuck pixel fixer flashes bright colors and is shown behind a photosensitivity warning. It may help a temporarily stuck pixel but cannot repair dead or damaged pixels, and results are not guaranteed.
We re-test the tool on small phones (320 px wide) up to large desktops whenever we change it. If you spot something that looks wrong, please tell us. Fixes usually ship within days.
Contact
Questions, ideas or bug reports are welcome on our contact page.