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Batch Image Resizer

Drop a batch of images and resize them by width, longest edge, box crop and more. Make several sizes (say 320, 640 and 1280) from each image in one go, then copy ready-made srcset HTML. Your images are never uploaded.

On-device・No upload

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

1Choose images

Drop files here (multiple allowed)

or

Images are processed in this browser on your device and never uploaded.Accepts: JPEG / PNG / WebP / AVIF / GIF / BMP / HEICUp to 50 MB per filePaste (Ctrl+V) also works
Resize settingsLongest edge · 1280 · Keep original

2Size

The longer side becomes the given length, whether the photo is portrait or landscape. Best for mixed orientations.

Separate values with commas or spaces to make several sizes from one image at once (up to 8). e.g. 320, 640, 1280

On: images smaller than the target keep their size. Off: they are stretched to the target (quality drops).

Quick settings

3Output

Output formats (pick one or more)

Pick several formats to get every size in each of them — handy for a <picture> snippet.

Quality
Example: IMG_0001_1280x853.jpg

Tokens: {name} original name · {w} width · {h} height · {size} requested size · {n} counter · {ext} extension. The extension is added automatically.

On: PNGs are recompressed to shrink the file (the picture does not change). Outputs over 4 megapixels are skipped automatically, because it would take too long, and keep the browser’s own PNG. Off: every PNG is written as the browser makes it.

Even with “Keep original”, GIF and BMP are written as PNG and HEIC as JPEG, because there is no encoder for those formats.

EXIF, GPS and ICC metadata are not written to the output (they cannot be kept). Orientation is applied to the pixels.

How to use

  1. Drop images or click “Choose files” (multiple files are fine; “Try a sample” loads two demo photos). Resizing starts with the current settings as soon as you add them.

  2. Pick a “Resize method” and type the size. Separate values like “320, 640, 1280” to make several sizes from every image. The crop and pad methods take “1080x1080”.

  3. Choose the output formats (one or more): keep the original, or JPEG, PNG, WebP, AVIF. Then set the quality and the file-name pattern.

  4. After changing settings, press “Redo with these settings”. Check original → new size, file size and change in the list, and use “Compare” to look at the result.

  5. Download files one by one or as a ZIP. For websites, copy the HTML snippet below the results.

What it does

Eight resize methods

Fixed width, height, longest or shortest edge; fit inside a box; fill a box and crop (nine anchor positions); pad to a box; or percent. “Never enlarge small images” is on by default, so low-resolution pictures are not stretched into blur.

Several sizes and formats from one image

List sizes like “320, 640, 1280” and tick several formats such as JPEG, WebP and AVIF. Each image is decoded once and every size is rendered from it. Sizes that would end up identical because nothing is enlarged are merged automatically.

Copy-ready srcset and picture HTML

From the generated file names and widths it writes <img srcset> and <picture> (AVIF → WebP → JPEG <source> elements). width and height attributes are included to avoid layout shift (CLS).

Smoother downscaling

Big reductions are done in halving steps with a final smooth pass, so fine stripes and small text stay cleaner than a single jump would. EXIF orientation is applied when the image is read.

Name patterns without collisions

Combine the original name, width, height, requested size, a counter and the extension, e.g. {name}_{w}x{h}. Duplicates get _2, _3 automatically, so nothing is overwritten inside the ZIP.

Responsive, stoppable, retryable

Work runs in background Web Workers and can be stopped any time. Retry just the files that failed, and include a report.csv in the ZIP.

Use cases

  • Prepare blog or shop photos in several widths for srcset on desktop and mobile
  • Bring a pile of phone photos to the same long edge (e.g. 1600 px) for sharing or submission
  • Crop everything to a 1080×1080 square or a 16:9 box for social media or a catalogue
  • Make product shots of every shape the same size by padding them with a background colour
  • Output list thumbnails and large detail images in one pass with a consistent naming rule

Supported formats

Input

JPEG (.jpg / .jpeg / .jfif)PNGWebPAVIFGIF (still)BMPHEIC (only in browsers that can open it, e.g. Safari)

Output

JPEGPNGWebPAVIFKeep original (GIF and BMP become PNG, HEIC becomes JPEG)

Capability matrix

FeatureSupportNotes
Resize by width, height, longest edge, shortest edge or percentSupportedAspect ratio is preserved
Fit inside a box, fill a box and crop, pad to a boxSupportedNine anchor positions for crop and pad
Several sizes at onceSupportedUp to 8 sizes per image, 100 megapixels in total
Several formats at once (JPEG / PNG / WebP / AVIF)Supported—
<img srcset> / <picture> HTML generation and copySupportedsrcset only when every size keeps the same aspect ratio
Never enlarge small images (default)SupportedTurn off to stretch to the target (quality drops)
EXIF orientation appliedSupported—
Name patterns and automatic duplicate-name avoidanceSupported—
Compare with the original, per-file download, ZIP, report.csvSupported—
Keeping EXIF / GPS / ICC metadataNot supportedAlways removed (cannot be kept)
Animated GIF / APNG / animated WebPNot supportedNot processed, to avoid losing the animation
HEIC (iPhone photos)PartialWorks in Safari; other browsers cannot open HEIC
Wide gamut (Display P3) preservationPartialOutput is converted to sRGB
Choosing a resampling algorithm such as LanczosNot supportedUses stepwise halving plus the browser’s high-quality smoothing
Target file size (under N KB) or PNG colour reductionNot supportedUse “Image Compressor” to shrink file size

Limits & notes

  • Up to 100 files per batch; 50 MB per file and 500 MB in total; source images up to 64 megapixels (e.g. 8000×8000).
  • Each output up to 16,384 px per side and 50 megapixels; all sizes made from one image together up to 100 megapixels. “sizes × formats × files” must stay at or below 600.
  • Up to 8 sizes per image.
  • AVIF encoding takes seconds to tens of seconds per image. Choose WebP when speed matters.
  • PNG optimisation (a setting, on by default) takes a few seconds per image and is skipped automatically for outputs over 4 megapixels; the list says so and the browser’s own PNG is written as is.
  • Transparent areas become the chosen background colour (white by default) when saving as JPEG.
  • ICC colour profiles are not preserved; images are output as sRGB.
  • Processing uses your device’s CPU and memory; older phones may be slow with many large images.

Privacy & safety

Reading, resizing, encoding and zipping all happen inside your browser. Images and file names are never sent to or stored on a server. Only the image engine (WebAssembly) is downloaded the first time you use it.

FAQ

How do I export several sizes at once?
Type the sizes separated by commas or spaces, such as “320, 640, 1280”. With the width method each value is a width, with longest edge each is the long side; up to 8 sizes per image. Tick several formats too and you get sizes × formats files.
How is this different from the Image Compressor and Image Converter?
This tool is about changing dimensions: crop, pad, several sizes and srcset HTML. Use Image Compressor when the goal is a smaller file, and Image Converter when the goal is another format. You can still set format and quality here at the same time.
Why aren’t small images enlarged?
“Never enlarge small images” is on by default. Stretching only adds blur and file size, so images smaller than the target keep their original size. Turn the setting off if you do want them enlarged.
How do I use the srcset output?
Enter sizes like “320, 640, 1280”, process, then copy the HTML snippet and set “Image URL (path)” to where you will host the files. Browsers download only the image that fits the screen, so phones fetch the small ones. Set sizes to roughly how wide the image is displayed.
Are EXIF and GPS data kept?
No. Re-encoding removes EXIF, GPS and ICC metadata, and there is no option to keep it. Orientation is applied to the pixels, so photos never end up sideways.
Are my images uploaded?
No. All processing happens in your browser; images never leave your device.

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