Free image upscaler — increase resolution online without uploading
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About Image Upscaler
Image Upscaler increases the resolution of your images up to 16x using high-quality browser-native interpolation. Upload a JPG, PNG, or WebP file, pick a scale factor (2x, 4x, 8x, or 16x), choose your output format and quality, and download the result. Everything runs locally in your browser — your images are never uploaded to a server. Output is capped at 16,384 px on any side to stay within browser limits, and you'll see warnings whenever the requested scale would exceed that.
Key Features
- 2x, 4x, 8x, and 16x upscaling options
- High-quality multi-step interpolation
- Support for JPG, PNG, and WebP formats
- Choose output format (PNG, JPEG, WebP) with quality slider
- 100% client-side — images never leave your browser
- Automatic dimension capping at browser limits
- Preview original and upscaled side by side
- Free to use without registration
Use Cases
- Enlarge small images for print at higher DPI
- Increase thumbnail or web-image resolution for sharper display
- Upscale digital art, logos, and illustrations
- Prepare higher-resolution product photos for e-commerce
- Resize old or low-res photographs for modern screens
Pro Tips
- 2x upscaling gives the sharpest results — higher factors introduce more interpolation smoothing.
- Use PNG output for lossless quality; switch to JPEG or WebP and lower the quality slider to reduce file size.
- Very large scale factors on small source images will produce soft results because there is not enough detail to extrapolate.
- If the browser warns about capped dimensions, use a lower scale or crop/resize the source first.
- For best results, start with the highest quality source image you have.
Frequently Asked Questions
How does this upscaler work?
The tool loads your image into an HTML5 Canvas element and redraws it at the target resolution using the browser's highest-quality interpolation algorithm. For scale factors above 2x, upscaling is done in multiple 2x steps for smoother results. Everything runs in your browser — no data is sent to any server.
What scale factors are available?
You can choose 2x, 4x, 8x, or 16x. Each factor multiplies both width and height, so a 500×300 image at 4x becomes 2000×1200. At 16x the same image would become 8000×4800. If the output would exceed the browser's maximum canvas size (16,384 px per side), dimensions are automatically capped and you'll see a warning.
What's the maximum file size I can upscale?
The input file size limit is 10 MB. The more important constraint is output pixel count — if the resulting image exceeds roughly 268 million pixels (about 16,384×16,384), the browser cannot allocate the canvas and the tool will let you know before attempting.
Which output formats are supported?
You can export as PNG (lossless, larger files), JPEG (lossy, smaller files), or WebP (lossy, smallest files). For JPEG and WebP you can adjust the quality slider from 10% to 100%.
Will upscaling make a blurry image sharp?
No. Browser-based interpolation smoothly scales existing pixels but cannot invent new detail. A blurry or heavily compressed source will produce a larger but equally soft result. For best outcomes, start with the highest-resolution source you have.
Is my image uploaded anywhere?
No. All processing happens locally in your browser using the Canvas API. Your image data never leaves your device.