What it does
Overlay two normalized views to inspect changes with a slider. Both images are centered at the same scale while preserving orientation and aspect ratio.
When to use it
Use this tool when its stated local workflow and limits match your task. Review the result before relying on it.
Steps
- Select local Before and After images.
- Process them and review each image’s dimensions.
- Drag the slider or use arrows, Home and End on a keyboard.
Verifiable example
Input: Before is 80 × 60 px and After is 40 × 30 px.
Expected result: A shared 80 × 60 canvas: the second image is centered without upscaling or distortion; 0% shows After and 100% shows Before.
Common mistakes
Renaming an SVG, animated image or corrupt file to .png does not make it valid. Choose a supported original file, then check dimensions and format.
Limitations
- Two static JPEG/PNG/WebP files; up to 5 MiB, 8 megapixels and 4096 px per file. Shared view up to 800 × 600.
- No automatic scene alignment, pixel-difference calculation or equality certification. Cancellation is cooperative: native decoding may finish before releasing resources.
Frequently asked questions
Is my input uploaded?
No. This workflow runs locally in the browser. Visiting the site still downloads software and public resources; inputs and results are not stored automatically.
Does this certify security or authenticity?
No. Read the stated scope and limitations. Browser memory, extensions and the operating system remain outside a guarantee of forensic erasure.