Upscale Image

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Upscale Image

Enhance and enlarge images using advanced Lanczos interpolation.
Improve image quality while scaling up with minimal artifacts.

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Supported formats: JPG, PNG, WebP (max 10MB)

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About this image upscaler

Enlarging an image means inventing pixels that were never captured, and how those pixels are guessed makes all the difference. The browser’s default enlargement blends each new pixel from its immediate neighbours, which produces the soft, slightly gummy look everyone recognises as “blown up”.

This tool offers several interpolation algorithms of increasing sophistication, up to an edge-directed method that detects the direction of edges in the source and samples along them rather than across them — which is what keeps a diagonal line looking like a line instead of a staircase. An unsharp mask can be applied afterwards to restore the crispness that any enlargement costs. Scaling runs from 1.5× to 4×.

Every algorithm runs in your browser, including the heavier ones. Nothing is uploaded, so processing time depends on your machine rather than on a queue.

How to upscale an image

  1. Add your image. Start with the largest, cleanest version you have — upscaling amplifies existing compression artefacts along with everything else.
  2. Choose a scale factor. 1.5×, 2×, 3× or 4×. Beyond 2× the returns diminish quickly on photographic content.
  3. Pick an algorithm and sharpening. The highest-quality option is slowest; light sharpening suits most images. Details below.
  4. Choose the output format and convert. PNG preserves the result losslessly; JPG produces a smaller file. Large images at 4× take a while.

What the algorithms actually do

AlgorithmMethodSpeed
AI-Level / Ultra / Edge-DirectedEdge-directed interpolation with anti-aliasing and denoisingSlowest
LanczosWindowed sinc filter over a wide pixel neighbourhoodSlow
BicubicCubic interpolation over a 4×4 neighbourhoodFast
BilinearLinear blend of the four nearest pixelsFastest

One point of honesty: the top three options share the same edge-directed implementation, and none of them is a neural network. “AI-Level” describes the intended quality tier, not a generative model — no detail is hallucinated, and nothing that was not in the source is invented. What you get is the best guess classical interpolation can make, which for line art, logos and screenshots is genuinely excellent, and for a blurry photograph is still a blurry photograph, only larger.

What upscales well

SourceOutcome at 2×
Logos and line artExcellent — edges stay clean
Screenshots of interfacesGood — text remains readable
Sharp, well-lit photographsGood — noticeably better than default scaling
Small JPEGs saved from the webPoor — compression blocks are enlarged too
Out-of-focus or motion-blurred shotsPoor — blur cannot be undone

Frequently asked questions

Does this use AI to add detail?

No. Despite the name of the top quality preset, all the algorithms here are classical interpolation — sophisticated, edge-aware interpolation, but interpolation. No detail is invented that was not in the source image.

Which algorithm should I choose?

The highest quality setting for anything that matters, since the difference is most visible on edges. Drop to Bicubic if a large batch is taking too long; Bilinear only when speed is the sole concern.

How much can I enlarge before it looks bad?

2× is reliable for most content. 3× and 4× work well for logos and line art but show their limits on photographs, where they mostly produce a larger version of the same softness.

Why does my upscaled photo look worse than the original?

Enlargement magnifies everything, including JPEG compression blocks, sensor noise and focus errors. A small image saved from a website has all three. Starting from the highest-quality original you can find matters more than any setting here.

What does sharpening do?

It applies an unsharp mask that increases local contrast at edges, restoring some of the crispness enlargement costs. Light suits most images; Strong can introduce visible halos around high-contrast edges.

Is my image uploaded?

No. All the processing happens inside your browser, which is why large images at high scale factors take time — the work is being done by your own machine.

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