# Image Upscaler 4x (AI) — yeezhan.com
> One-time pay-per-task emergency tool to make your file ready for submission.
> No credits, no balance. One payment unlocks one task result, valid for 24 hours.

Tool domain: https://image-upscale.yeezhan.com
Skill definition: https://image-upscale.yeezhan.com/skill/SKILL.md
API documentation: https://image-upscale.yeezhan.com/api/docs

## What this tool does
Real-ESRGAN 4x super-resolution — make small images print-ready without the mush.

## Typical user problems
- Small images cannot print or fill large screens — plain interpolation just makes blur bigger. Real-ESRGAN hallucinates crisp edges and texture the way your eye expects them.
- The only copy of the photo is 500px wide and the print needs 300 DPI at A4. AI upscaling adds plausible detail instead of blurry interpolation.

## Parameters
- scale: enum, required. 放大倍数

## Pricing
- Watermarked preview: free, no login required
- Final clean output: $2.99 one-time per task
- Require login (email/phone OTP) to complete payment
- Result available for download 24 hours after payment

## Limitations
- Max input 20 MB
- 2× or 4× output as PNG
- CPU inference: large images take a minute or two