Image Upscaler
Upscale any image 2x, 3x, or 4x with 3 upscale methods: smooth bicubic, sharp nearest-neighbor, or Lanczos 3-lobe resampling, plus an optional edge-enhance unsharp mask. 100% browser-based, download PNG/JPG/WebP.
Click, drop, or paste an image
🔒 100% browser-based · No upload to server · No signup
3 Upscale Methods
Smooth (bicubic), Sharp (nearest-neighbor, keeps hard pixel edges), or Lanczos 3-lobe resampling for the sharpest, most detailed photo upscale.
Edge Enhance
Optional unsharp mask applied after upscaling — boosts edges and detail for crisper results. Toggle on or off; off by default.
100% Private
Your image never leaves your device. All upscaling happens in your browser using the Canvas API — no upload, no signup.
2x/3x/4x · PNG/JPG/WebP
Scale 2x, 3x, or 4x and export as PNG (lossless), JPG (smallest), or WebP (modern). Output is capped at 8192px to avoid crashes. No watermark.
What is the difference between Smooth, Sharp, and Lanczos?
Smooth uses bicubic interpolation (imageSmoothingEnabled + high quality) — soft, natural results. Sharp uses nearest-neighbor (imageSmoothingEnabled=false) — blocky, pixelated, keeps hard edges, great for pixel art. Lanczos implements 3-lobe Lanczos resampling (sinc(x)·sinc(x/3)) manually on ImageData — the sharpest, most detailed upscale, ideal for photos but slower.
What does Edge Enhance do?
It runs an unsharp mask after upscaling: sharpened = original + 0.6 × (original − blurred), where the blurred image is a 3×3 box blur of the upscaled pixels. This boosts edges and fine detail. It is off by default — turn it on when an upscaled photo looks too soft.
Is the upscaler free?
Yes. 100% free, no signup, no watermark, no daily limit. All three methods (Smooth, Sharp, Lanczos) and Edge Enhance are available to everyone.
What is the max upscale factor and size?
4x. To protect the browser from running out of memory, the output is capped at 8192px on the longest side — e.g. a 3000×3000 image at 4x (which would be 12000×12000 ≈ 576MB) is automatically scaled down to 8192×8192. The real output dimensions are always shown to you before you download.
Does my image leave my device?
No. All processing happens in your browser using the Canvas API. Your image is never uploaded to any server — not even for the Lanczos method, which runs entirely in JavaScript.
Ready to try Image Upscaler?
Free, no signup, no watermark. 100% browser-based. Your image never leaves your device.
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