How does the image upscaler work?

It uses Lanczos-3 resampling — the same algorithm used by professional image editors like Photoshop and GIMP for high-quality enlargement. After upscaling, an unsharp mask pass sharpens edges and recovers detail. Everything runs entirely in your browser via the Canvas API. No upload required.

What is the difference between 2× and 4× upscale?

2× doubles the width and height of your image (4× the pixel count). 4× quadruples both dimensions (16× the pixel count). Use 2× for most cases — it is fast and works on any image size. Use 4× only for small images (under 4 MP) where you need maximum output resolution.

Can this recover a blurry or heavily compressed photo?

It significantly improves pixelated or low-resolution images by adding sharp sub-pixel interpolation. However, detail that was never captured in the original cannot be fully reconstructed. For the best results, start with the sharpest source image available.

Why does upscaling take some time?

Lanczos-3 is computationally intensive — it evaluates multiple surrounding pixels for every output pixel to produce smooth, sharp results. 2× on a 2 MP image typically takes 5–15 seconds. 4× on the same image takes longer due to 4× more output pixels.

What image formats are supported?

JPG, PNG, and WebP input. The output is always PNG to preserve maximum quality after upscaling.

Is there a size limit?

2× upscale supports images up to 16 MP. 4× is limited to images under 4 MP to prevent the browser running out of memory. If your image is larger, resize it first using the Image Resizer tool.

Image Upscaler — Increase Image Resolution Free Online

Upscale images 2× or 4× using Lanczos-3 resampling with unsharp masking. Adds genuine sharpness — not stretched pixels. Compare before and after with a drag slider. No uploads, 100% free.

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Instant

What is Image Upscaler — Increase Image Resolution Free Online?

An image upscaler increases the resolution of a photo or graphic while preserving as much sharpness and detail as possible. Unlike basic resizing which stretches existing pixels and creates blur, our tool uses Lanczos-3 resampling — the same algorithm used by professional image editors like Photoshop, GIMP, and Lightroom. After upscaling, an unsharp mask pass sharpens edges and recovers fine detail. Everything runs entirely in your browser using the Canvas API — your images never leave your device.

How to Use Image Upscaler — Increase Image Resolution Free Online

1Upload a JPG, PNG, or WebP image using the drop zone.
2Choose 2× (doubles resolution, recommended) or 4× (quadruples resolution, for small images only).
3Click Upscale — the tool processes your image entirely in the browser.
4Drag the before/after comparison slider to see the quality difference.
5Click Download PNG to save your upscaled image.

Key Features

Lanczos-3 resampling with unsharp masking — genuine sharpness, not stretched pixels
2× and 4× upscale options
Interactive drag before/after comparison slider
Runs 100% in browser via Canvas API — no uploads
Supports JPG, PNG, and WebP input

Benefits

Make low-resolution images sharp enough to print large
Recover usable detail from old or pixelated photos
See the exact improvement before downloading
No account, no watermark, no server upload

Why Use Irreva for Image Upscaler — Increase Image Resolution Free Online?

Make low-resolution images sharp enough to print large

Recover usable detail from old or pixelated photos

See the exact improvement before downloading

Runs 100% in your browser — files never leave your device.

No account, no sign-up, no subscription — free forever.

Works on any device: desktop, tablet, or mobile.

Frequently Asked Questions

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