How AI Image Compare Works
Compare two images and get a narrated report of what changed, plus a pixel-diff heatmap.
Try it free →Step-by-step process
- 1
Add your image
Drop or select the image you want to process — it stays on your device.
- 2
Run the model in-browser
AI Image Compare loads its model (~500 MB) once, caches it, then runs locally in a worker. No upload.
- 3
Download the text
Preview the result and download the text. Re-run with different settings anytime.
Frequently asked questions
How does it compare?
It combines a per-pixel ΔE difference pass with a vision-model narration of what changed.
Do the images need to match size?
They are aligned to a common size before comparison for best results.
Is it free to use?
Yes — AI Image Compare is completely free. No account, no watermark, no credits, and no usage limits.
Do my files or prompts ever leave my device?
No. Everything runs locally in your browser via WebAssembly/WebGPU — there is no server that receives your files, prompts, or results.
Which browser and hardware do I need?
A modern browser. Chrome and Edge get WebGPU acceleration for the fastest results; Firefox and Safari run via WebAssembly. The model (~500 MB) downloads once, then is cached for offline use.
Can I use the results commercially?
Yes. You own everything you create — NSS makes no claim to the images, videos, or text you process or export.
Does it work on mobile?
Lightweight tools run on phones; heavier models prefer a desktop with a GPU. The tool picks the best path for your device and falls back gracefully where needed.
Where can I see a step-by-step guide?
Yes — there is a full walkthrough at /how-it-works/ai-compare-images.