Free Image Upscaler

Enlarge a small image up to four times its size using Lanczos resampling and a sharpening pass. No account, no watermark, no queue.

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Scale

How to Use It

  1. Drop in the small image you want bigger.
  2. Pick a scale. Two times is the safest, four times is the practical ceiling.
  3. Leave sharpening on Medium unless the image is line art or a screenshot, where Strong looks better.
  4. Choose PNG if the image has transparency, JPG if it does not and you care about file size.
  5. Press the button. The enlarged file downloads straight away.

What to Expect at Each Scale

Scale 800 x 600 becomes Realistic result
1.5x1200 x 900Almost indistinguishable from the original.
2x1600 x 1200Clean. This is the sweet spot.
3x2400 x 1800Soft up close, fine at arm's length.
4x3200 x 2400Visibly smoothed. Useful for print size, not for detail.

The Honest Limits

This tool uses Lanczos resampling, which is the best of the classic algorithms. It works out each new pixel from the ones around it, using a weighting curve that keeps edges crisper than bilinear or bicubic does. Then it runs an unsharp mask so the result does not look like a soft blob.

What it does not do is invent detail. A generative upscaler guesses at eyelashes, brick texture and blades of grass that were never in the file. That guessing produces impressive results and also invents things that were never there, which matters if the image is evidence, a document, or a face.

Rule of thumb: if the detail is not in the original pixels, no upscaler can recover it. It can only produce a larger, smoother version, or a larger invented one. Pick which of those you want before you start.

Doing the Same Thing in GIMP

  1. Open the image, then go to Image > Scale Image.
  2. Set the width. The height follows automatically while the chain icon is linked.
  3. Change Interpolation to NoHalo or LoHalo. Both handle enlargement better than Cubic.
  4. Press Scale, then apply Filters > Enhance > Sharpen (Unsharp Mask) with a radius near 2 and a modest amount.
  5. Export. Sharpen last, always, and only once.

For a folder of images, the Script-Fu generator writes the batch script for you.

Common Questions

Why is my enlarged photo blurry?

Because enlargement spreads the same information over more pixels. Try a lower scale, or turn sharpening up one step. If the original is heavily compressed, the JPG artefacts get enlarged too, which reads as smeared blocks.

Will this fix a blurry photo?

No. Upscaling and deblurring are different problems. A photo that was out of focus stays out of focus, just larger.

Is there a size limit?

Uploads cap at 15 MB, and the result is capped at 50 megapixels. A 4x scale on a 12 megapixel photo goes past that, so pick a smaller factor for large sources.

What about printing?

Work out what you actually need first with the DPI and print size calculator. Plenty of images that look too small on screen already have enough pixels for the print size you want.

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