Image Enlarger — Upscale 2×, 3×, 4× (Lanczos)
Browser image enlarger with Lanczos interpolation (not AI)
Runs in your browser · nothing is uploaded
This is not AI upscaling. Lanczos interpolation fills the gaps between pixels smoothly, so it cannot invent detail that is not in the original (small text, fine skin texture). The goal is a larger picture without jagged steps.
Drop a photo to enlarge
Add one JPG, PNG or WebP (up to 50 MB) or paste it with Ctrl+V (⌘V on Mac). Nothing is uploaded.
Enlarging softens edges a little. Light suits most photos, strong suits text or drawings with crisp edges. Too much can leave bright halos along edges.
Saved in the original format (JPG and WebP at quality 92, PNG lossless), with the scale added to the name, such as -2x.
The picture is redrawn, so the original EXIF data (camera, time, GPS location) is not carried over; the photo's rotation is applied. Nothing is uploaded.
What it is
A tool that makes small images 2, 3 or 4 times larger. Simply stretching pixels, as basic editors do, gives jagged steps and a blocky look. This tool uses Lanczos interpolation, a weighted average of the surrounding pixels, to join edges smoothly, and can then sharpen them slightly with an unsharp mask. Under the result you see the same area enlarged without interpolation next to the Lanczos version, so the difference is easy to judge.
It is not AI restoration. Detail that is not in the original cannot appear, so smudged text and tiny faces stay soft. It is the right tool for making a profile picture or icon somewhat bigger, or for reaching the pixel count a print needs.
How to use
- Drop one JPG, PNG or WebP on the dashed area or click Choose photo.
- Pick a Scale: 2×, 3× or 4×. The output size is shown at once.
- Under Sharpen, choose Off, Light or Strong.
- Click Enlarge, then Save enlarged photo.
How it works
- Interpolation: Lanczos3 (a sinc-weighted average over a 6×6 neighbourhood), computed by the MIT-licensed pica library, in a Web Worker when possible.
- Sharpening: unsharp mask. Light is amount 80, radius 0.6 px, threshold 2; Strong is amount 160, radius 0.8 px, threshold 1 (pica’s scale).
- Limits: 64 megapixels on a computer, 16,777,216 pixels on iPhone and iPad, 16,384 px per side. Beyond that the real factor is reduced.
- Saving: same format as the original (JPG and WebP at quality 92, PNG lossless), with the factor in the name, such as
-2x. EXIF data is not carried over.
Examples
| Original | Setting | Result |
|---|---|---|
| profile.jpg 400×400 | 4×, Light | profile-4x.jpg 1600×1600 |
| icon.png 128×128 | 2×, Strong | icon-2x.png 256×256 |
| scan.jpg 3000×2000 | 4× | saved at about 3.27× (9797×6531) |
To shrink or set exact pixel sizes use the image resizer; if the enlarged file is large, run it through the image compressor.
FAQ
How is this different from an AI upscaler?
An AI upscaler uses a trained model to invent plausible detail. This tool fills the gaps between pixels mathematically (Lanczos), so blurry text does not become readable and faces are not restored. In return the result stays faithful to the original, no model has to be downloaded, and the photo never leaves your browser.
How large can it go?
2×, 3× or 4×. The result is capped at 64 megapixels (about 8000×8000) on a computer and 16,777,216 pixels on iPhone and iPad; above that the real factor is lowered and the page tells you.
When should I sharpen?
Enlarging softens edges, so Light is on by default. Strong suits text and drawings with crisp edges; Off can be better for smooth skin. Too much sharpening leaves bright halos along edges.
Can it set a print resolution (DPI)?
It increases the pixel count. A 1200×1800 px photo enlarged 2× becomes 2400×3600 px, enough pixels for about 8×12 inches at 300 DPI. The DPI value itself is set in your printing software.
Is my photo uploaded?
No. The resizing (pica library) and saving run in your browser.
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