Image Upscaler — Enlarge Images 2×, 3×, or 4× Free Online, No Upload
Enlarge images 2×, 3×, or 4× using Lanczos resampling — sharp results, runs entirely in your browser. No upload, no account.
Drop an image here or browse files
JPEG · PNG · WebP · GIF · BMP
About the Image Upscaler
This tool uses Lanczos3 resampling — a high-quality interpolation algorithm that produces sharper edges than standard bilinear or bicubic scaling. Everything runs in your browser via the pica library — your image is never uploaded.
Output format tips
PNG — Best choice for upscaled images. Lossless — preserves every pixel from the resampler without re-compression artifacts.
JPEG / WebP — Smaller files. Use quality 90%+ to avoid compression artifacts on top of the upscaled result.
Lanczos resampling cannot invent detail that doesn't exist in the source. For AI-based upscaling, tools like Upscayl use neural network models.
Related tools
After upscaling, reduce file size with the Image Compressor — PNG output from the upscaler is lossless and large; compressing to WebP at quality 90 recovers most of that size. To change format or convert an image first, the Image Converter handles JPEG, PNG, and WebP in both directions.
Frequently Asked Questions
Are my images uploaded to a server?
No. The Image Upscaler runs entirely in your browser using the pica JavaScript library. Your images are processed locally and never transmitted anywhere.
Is the Image Upscaler free?
Yes — completely free. No account, no signup, and no file size limit imposed by a server.
Do I need an account?
No account or login required. The tool runs directly in your browser.
What scale factor should I use?
2× works well for most images — it doubles the resolution with minimal visible degradation. 3× or 4× is useful for very small source images (icons, thumbnails) where you need a significantly larger version. Higher scales produce larger files and take longer to process.
Will the upscaled image look blurry?
Lanczos3 resampling produces sharper edges than standard bilinear or bicubic scaling. However, upscaling cannot add detail that does not exist in the original — if the source image is very low resolution, the upscaled version will be larger but not more detailed. Enable the Sharpen option to reduce softness.
What is the maximum output resolution?
The tool warns when the output would exceed 64 megapixels, as very large images can exhaust browser memory. For most upscaling tasks, 2× stays well within this limit.