Image Upscaler – Enlarge Images 2x 3x 4x Online (Free)
Free online image upscaler. Enlarge any PNG, JPG, WebP by 2×, 3×, or 4× using high-quality Lanczos-3 resampling. Much sharper than browser default. Runs entirely in your browser.
Example Output
Lanczos-3 resampling produces noticeably sharper enlargements than the browser's default bilinear scaling.
logo-2x.png (1024×1024, sharp edges, no blur)
What is Image Upscaler (Lanczos)?
Enlarge images by 2×, 3×, or 4× with Lanczos-3 resampling — the same algorithm used by Photoshop, GIMP, and ffmpeg for sharp resizing. The output is meaningfully sharper than the browser's default bilinear scaling, especially on text, edges, and graphic art. No AI model required, runs on any device.
Why use this tool?
- Touch-friendly UI, fine on phones for on-the-go edits
- No registration, account, or installation required
- No API keys to manage and no rate limits to monitor
- Your original file is never uploaded — sensitive screenshots stay on your device
- Output preserves color profile and metadata except when stripping is explicitly requested
How to use
- Upload an image (PNG / JPG / WebP up to 30 MB)
- Pick a scale (2×, 3×, or 4×)
- Choose output format (PNG lossless, JPG/WebP for smaller)
- Click Upscale and download
Examples
Tiny screenshot blown up
A 400×300 documentation screenshot upscales to 1600×1200 with text still readable — bilinear would smear it.
Logo enlargement
A 256×256 brand logo becomes a 1024×1024 PNG for a hero section, edges remain crisp.
Pixel-art preservation
For sharp pixel art, use a different algorithm — but for photo-realistic upscales, Lanczos is industry-standard.
Common use cases
- Enlarging screenshots for documentation
- Upscaling logos for high-DPI use
- Photo prints from web-resolution sources
- Making thumbnail sources into full-size headers
- Anywhere you'd use Photoshop's "Bicubic Sharper" today
Troubleshooting
- Upscaled photo still looks soft
- Lanczos preserves existing detail — it can't create what isn't there. For "AI-style" detail enhancement, you need a true neural upscaler (Real-ESRGAN, SwinIR), not Lanczos.
- Output is huge as PNG
- PNG is lossless and high-res files get big. Switch to JPG quality 95 or WebP 90 — 5-10× smaller for negligible quality loss on photos.
- 4× output rejected as too large
- There's an 8000 px guardrail to avoid mobile-browser OOM. Downscale the source first if you need 4× of a 3000px input.
Frequently Asked Questions
No — this is high-quality Lanczos-3 resampling, the algorithm pro photo editors use for sharp resizing. AI upscalers (Real-ESRGAN, SwinIR) need a 100+ MB model; Lanczos works on any device with zero downloads.
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