Image Resizer
Resize images to exact dimensions with advanced algorithms. Batch processing, preset dimensions, and smart scaling options.
100% private
Images never leave your browser
Pixel-accurate
Lanczos, bicubic, Magic Kernel
Batch resize
Whole folder in one pass
Target ratio: 1920:1080
Drop images here
or click to browse
Maximum file size: 100MB
How It Works
Set dimensions
Enter custom dimensions or choose from presets
Upload images
Drag & drop or click to select your files
Download resized images
Get your perfectly sized images instantly
FormatFuse's image resizer downscales or upscales one image or a whole folder at a time. It uses the Lanczos and bicubic algorithms built into the browser's Canvas API to preserve detail even at aggressive size reductions, so a 4000×3000 photo resized to 800×600 keeps sharp edges instead of looking soft.
Presets are built in for the most common targets — 1920×1080 for HD, 1080×1080 for Instagram, 1200×630 for social cards, and so on. You can also type custom dimensions, lock the aspect ratio, or set a single target dimension and let the other be calculated automatically. Output can be saved in the original format or switched to WebP, PNG, or JPG in the same pass.
Because resizing runs entirely in your browser, there is no file size limit imposed by our servers and nothing is uploaded. Batch resize a hundred product photos or shrink a single phone snapshot — either way your images stay on your device, and the output is ready to download immediately.
Image Resizer — Frequently Asked Questions
How do I resize an image without losing quality?
Downscaling with Lanczos interpolation (the default here) is effectively lossless for viewing — fine detail is preserved as pixels are combined. For absolute fidelity, keep the output in the same format as the input (PNG stays lossless; JPG and WebP re-encode). Upscaling cannot invent detail that was not in the source, so match or downscale from the original rather than enlarging.
Which resize algorithm should I pick?
Lanczos3 is the best all-round choice for photos — sharp without ringing artifacts. Mitchell is a gentler option for images with a lot of gradients. CatRom preserves fine edges, good for text and UI screenshots. HQX is tuned for pixel art and keeps hard edges. If you are unsure, leave it on Lanczos3.
Can I resize multiple images to the same size at once?
Yes — drop a folder onto the page and every image is resized with the same width, height, and algorithm. Outputs download individually or as a single ZIP. The aspect ratio lock is respected per-image, so source files with different ratios are handled gracefully.
Will the aspect ratio be preserved?
By default, yes — the tool keeps the source ratio and auto-calculates the missing dimension if you only supply one side. Unlock the ratio when you need an exact shape (for example 1080×1080 square for Instagram). When width and height are mismatched, the tool fits the image into the target and letterboxes transparent padding around it.
What image formats can I resize?
JPG, PNG, WebP, AVIF, HEIC, BMP, and GIF. You can also change the format on export — for example, resize a 12 MP phone photo and save it as a 200 KB WebP in one pass.
Is my image uploaded to a server?
No. Resizing runs locally using the browser's Canvas API and WebAssembly codecs. Your images never leave your device, so it's safe to resize confidential photos, product shots under NDA, or anything else.
How do I resize an image without losing quality?
Downscaling with Lanczos interpolation (the default here) is effectively lossless for viewing — fine detail is preserved as pixels are combined. For absolute fidelity, keep the output in the same format as the input (PNG stays lossless; JPG and WebP re-encode). Upscaling cannot invent detail that was not in the source, so match or downscale from the original rather than enlarging.
Which resize algorithm should I pick?
Lanczos3 is the best all-round choice for photos — sharp without ringing artifacts. Mitchell is a gentler option for images with a lot of gradients. CatRom preserves fine edges, good for text and UI screenshots. HQX is tuned for pixel art and keeps hard edges. If you are unsure, leave it on Lanczos3.
Can I resize multiple images to the same size at once?
Yes — drop a folder onto the page and every image is resized with the same width, height, and algorithm. Outputs download individually or as a single ZIP. The aspect ratio lock is respected per-image, so source files with different ratios are handled gracefully.
Will the aspect ratio be preserved?
By default, yes — the tool keeps the source ratio and auto-calculates the missing dimension if you only supply one side. Unlock the ratio when you need an exact shape (for example 1080×1080 square for Instagram). When width and height are mismatched, the tool fits the image into the target and letterboxes transparent padding around it.
What image formats can I resize?
JPG, PNG, WebP, AVIF, HEIC, BMP, and GIF. You can also change the format on export — for example, resize a 12 MP phone photo and save it as a 200 KB WebP in one pass.
Is my image uploaded to a server?
No. Resizing runs locally using the browser's Canvas API and WebAssembly codecs. Your images never leave your device, so it's safe to resize confidential photos, product shots under NDA, or anything else.