Are my photos uploaded to any external servers?

No. All super-resolution filtering, convolution matrices, bicubic interpolation, and pixel operations execute 100% locally in your browser's HTML5 Canvas sandbox. Your images never leave your computer.

What is the difference between Edge-Directed and Bilinear scaling?

Bilinear scaling calculates simple weighted averages of neighboring pixels, which smooths out sharp boundaries and makes enlarged photos look fuzzy. Edge-Directed super-resolution calculates local luminance gradients to detect edges, preserving sharp directional lines and avoiding ringing artifacts.

What algorithm should I use for pixel art and sprites?

Select 'Pixel Art (Integer Nearest)' mode. This preserves exact hard pixel grid boundaries without introducing interpolation blur or color bleeding, resulting in perfectly crisp 2x, 3x, or 4x retro game sprites.

Is there a file size or resolution limit?

Because processing happens directly in your browser's RAM, images up to 4096×4096 pixels can be processed comfortably on modern laptops and desktops.

Are my photos uploaded to any external servers?

No. All super-resolution filtering, convolution matrices, bicubic interpolation, and pixel operations execute 100% locally in your browser's HTML5 Canvas sandbox. Your images never leave your computer.

What is the difference between Edge-Directed and Bilinear scaling?

Bilinear scaling calculates simple weighted averages of neighboring pixels, which smooths out sharp boundaries and makes enlarged photos look fuzzy. Edge-Directed super-resolution calculates local luminance gradients to detect edges, preserving sharp directional lines and avoiding ringing artifacts.

What algorithm should I use for pixel art and sprites?

Select 'Pixel Art (Integer Nearest)' mode. This preserves exact hard pixel grid boundaries without introducing interpolation blur or color bleeding, resulting in perfectly crisp 2x, 3x, or 4x retro game sprites.

Is there a file size or resolution limit?

Because processing happens directly in your browser's RAM, images up to 4096×4096 pixels can be processed comfortably on modern laptops and desktops.

AI Image Upscaler & Super-Resolution Enhancer

Free client-side AI image upscaler. Enlarge photos and pixel art 2x, 3x, and 4x with edge-directed super-resolution and unsharp mask sharpening.

Try Sample Images:

Drag slider to compare

❮❯

Original: 120 × 120 px

Enhanced: 480 × 480 px (16x Pixels)

Processing: 14 ms

📂 Upload Your Image

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Drag & drop an image, or browse files

Currently using: Portrait Sample

⚙ Upscaling Configuration

Scale Factor

Reconstruction Algorithm Detects directional luminance gradients to reconstruct sharp edges and diagonal lines without blur.

Sharpening Intensity 45%

Artifact Suppression / Denoise 20%

Micro-Contrast Boost 15%

How Super-Resolution Image Upscaling Works

When an image is scaled beyond its original native resolution, the rendering pipeline must create new pixels where none existed before. Conventional interpolation methods like bilinear or nearest-neighbor filtering either blur fine micro-textures into a uniform smear or create blocky stair-step pixelation artifacts.

Super-resolution algorithms employ directional gradient estimation and high-frequency unsharp convolution kernels. By analyzing neighboring pixel variance in both horizontal, vertical, and diagonal vectors, the algorithm distinguishes between continuous textures and hard object boundaries, synthesizing crisp lines with minimal overshoot or halo ringing.

Comparison of Upscaling Algorithms

Algorithm	Best Use Case	Edge Sharpness	Processing Speed
Edge-Directed (NEDI)	Portraits, natural landscapes, architectural photos	Very High (preserves contours)	Fast (~15-30 ms)
AI Detail Sharpening	Text documents, high-contrast graphics, scans	Maximum (crisp unsharp mask)	Instant (~10 ms)
Photo Restoration	Heavily compressed JPEG photos with noise	Balanced (denoised + sharpened)	Fast (~25 ms)
Pixel Art Nearest	Retro 8-bit / 16-bit video game sprites	Exact Integer Hard Edges	Ultra Fast (<5 ms)
Hermite Bicubic	General-purpose continuous tone imagery	Moderate (smooth gradient)	Instant (<8 ms)

Tips for Best Upscaling Quality

Match Algorithm to Content: Never use edge-directed smoothing on pixel art sprites; always switch to "Pixel Art Nearest" to preserve the nostalgic retro grid.
Denoise Before Sharpening: If upscaling old scans or high-ISO night shots, increase Artifact Suppression to 30-40% to prevent the sharpening filter from exaggerating film grain.
Avoid Extreme Over-Sharpening: Keeping sharpening between 30% and 50% gives natural clarity. Setting it above 80% can cause noticeable white outline halos around dark text.

Frequently Asked Questions

Does upscaling create new genuine visual detail?: No algorithm can recover information that was never captured by the camera sensor. However, edge-directed super-resolution mathematically estimates where boundaries and gradients exist, producing clean geometric edges that look significantly sharper to human vision than standard blurry scaling.
What output format should I download?: We recommend lossless PNG format because it preserves every synthesized sub-pixel without adding re-compression JPEG artifacts.
Can I use this tool on my phone or tablet?: Yes. The tool runs on mobile Safari, Chrome, Firefox, and Edge with full touch support for the before/after comparison slider.

About this tool

How to use it

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Why it matters

Standard browser resizing produces blurry, muddy images because naive bilinear interpolation smears pixel boundaries. This client-side upscaler uses edge-directed interpolation kernels, unsharp masking, and local luminance contrast enhancement to reconstruct crisp edges, recover fine micro-textures, and eliminate JPEG compression blocking artifacts directly inside browser memory.

When to use it

Use this tool to enlarge old family photos, enhance low-resolution e-commerce product thumbnails, upscale retro gaming pixel art without blurring sharp sprite edges, or prepare web graphics for print publication without sending private photos to cloud servers.