Free Image Enlarger
Upscale images with stepped bicubic interpolation and unsharp masking — no blurry stretching. Works on photos, logos, screenshots, and line art. Bulk process up to 20 images.
Enlargement Settings
Drop images here or click to browse
JPEG, PNG, WebP · Up to 20 images
How the upscaler works
✓ Stepped interpolation — upscales in 2× passes with high-quality bicubic sampling, avoiding the blur of a single large stretch.
✓ Unsharp mask — applies a Laplacian sharpening kernel after each step to recover fine detail and edges.
✓ Best for 2–4× on photos. Line art, logos, and screenshots enlarge cleanly up to 8×.
✓ PNG output recommended for maximum quality — the file will be larger but pixel-perfect.
How to Enlarge an Image
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1. Upload your images
Drag and drop up to 20 images — photos, logos, screenshots, or line art — onto the drop zone.
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2. Choose a scale factor
Select a preset scale (1.5×, 2×, 3×, 4×, 6×, or 8×) or enter exact target dimensions. Aspect ratio is always preserved.
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3. Set sharpening level
Choose a sharpening amount: none, light, medium (recommended for photos), or strong (best for line art and logos).
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4. Download enlarged images
Each image is enlarged in your browser and ready to download. Click Download All for a ZIP of all processed images.
How the Algorithm Works
Stepped Upscaling
Instead of one large stretch (which smears detail), the image is doubled in small steps — max 2× per pass — with high-quality bicubic sampling at each step. This preserves edges and textures far better than a single-pass resize.
Unsharp Masking
After each step, a Laplacian sharpening kernel recovers fine detail lost during interpolation. The effect is similar to Photoshop's "Bicubic Sharper" mode — cleaner edges and texture without haloing artefacts.
When to Use Each Setting
Photos: 2–4× with Medium sharpening. Line art, logos, UI screenshots: up to 8× with Strong sharpening. PNG output keeps every pixel perfect; JPEG/WebP saves space for photos.
Frequently Asked Questions
What is stepped bicubic upscaling?⌄
Instead of stretching the image in one large jump (which smears edges), stepped bicubic upscaling doubles the image in multiple 2× passes — each time using high-quality bicubic sampling. More passes = better edge preservation. It's the same technique used by Photoshop's "Bicubic Smoother" mode.
How much can I upscale without visible degradation?⌄
For photos: 2–4× with medium sharpening gives excellent results. Beyond 4×, some softness becomes visible — best used with strong sharpening. For line art, logos, and screenshots with flat colours: up to 8× can look very clean because there are fewer gradients to interpolate.
Which sharpening level should I use?⌄
Medium (the default) works well for most photos. Strong is best for logos, screenshots, and line art where you want crisp edges. Light is suitable if you are enlarging for print and prefer a softer result. None is appropriate if you plan to sharpen in a separate editing step.
Is this the same as AI upscaling?⌄
No. This tool uses stepped bicubic interpolation with a Laplacian sharpening kernel — a high-quality traditional algorithm. True AI upscaling (like Topaz Gigapixel or ESRGAN) uses a neural network trained on millions of images and can produce sharper results, but requires much more processing power and usually a paid subscription.
Are my images uploaded to a server?⌄
No. All processing happens entirely in your browser using the Canvas API. Your files never leave your device.
What output format should I choose?⌄
PNG for logos, screenshots, and line art — it is lossless and preserves every pixel perfectly. JPEG or WebP for photos — they produce much smaller files. WebP gives the best compression with minimal quality loss and is supported by all modern browsers.