Can I stretch or resize the second image?

Yes. Drag the corner handles to resize freely, drag the edge handles to stretch one axis, or hold Shift on a corner handle to preserve the aspect ratio.

Image Overlay Compare – Free Online Tool to Compare Two Images Side by Side

Please upload two images

Tip: Drag Image 2 to move. Drag the handles to resize or stretch. Use the scale slider or pinch on touch to zoom.

Why use this image overlay tool?

This free online image comparison tool lets you overlay two pictures and instantly see their differences. It runs entirely in your browser — no sign-up, no uploads to any server, and no watermarks. Designers, developers, photographers, and QA testers can use it to verify pixel-perfect implementations, spot visual regressions, compare photo edits, and align design mockups.

Privacy-first: 100% client-side; your images never leave your device.
Adjustable opacity: Fade the overlay from 0% to 100% to reveal differences gradually.
Blend modes: Use Difference to instantly highlight any mismatched pixels.
Drag, stretch & zoom: Freely move, resize, or stretch the overlay; Shift-drag to keep aspect ratio.
Hide overlay: Quickly toggle the second image off to confirm the base without removing state.
Bilingual: English and Simplified Chinese interface.

Frequently Asked Questions

How do I compare two images for differences?

Upload two images, then drag the opacity slider or choose the Difference blend mode. The overlay layer can be moved or resized to align with the base image.

Are my images uploaded to a server?

No. All image processing happens locally in your browser using standard HTML5 and CSS. Your files never leave your device.

Can I stretch the second image to a different size?

Yes. Drag any corner handle to resize freely, drag an edge handle to stretch a single axis, or hold Shift on a corner handle to preserve the original aspect ratio.

Which image formats are supported?

Any image format your browser can display: PNG, JPEG, WebP, GIF, SVG, BMP, and more.