Bulk Image Resizer
Drop in dozens of images and resize them all in one click. Presets for social, thumbnails, and web. Pick fit, fill, stretch, or scale by percent. Output JPEG, PNG, or WEBP — packaged into a single ZIP, all in your browser.
Resize mode
Width (px)
The other dimension is computed per image from its own aspect ratio.
Or pick a preset
Output format
Applies to JPEG / WEBP. PNG is lossless and ignores this.
Filename suffix
One pipeline, many images
Resizing one image at a time is fine for a quick crop. The moment you have a folder of product photos, a batch of screenshots, or a whole shoot to push to the web, doing it one-by-one is the wrong tool. Bulk resize is built around a single decision—what shape do you want every output to take?—and then applies it to all of them.
Drop the images in, pick a preset or type a size, choose a mode and a format, and download a single ZIP. Everything is rendered locally on a canvas; the files never leave your browser.
Six resize modes — which one to pick
| Mode | What it does | Best for |
|---|---|---|
| Fixed width | You type a single target width. Every image is resized to that width and the height is computed per image from its own aspect ratio, so nothing is distorted or cropped. | Web delivery (“all images max 1920 wide”), blog post images, responsive uploads where height can vary per photo. |
| Fixed height | Mirror of fixed width: you type a target height and the width is computed per image from its aspect ratio. | Horizontal scrollers, banner strips, product thumbnails arranged in a row where every row item must be the same height. |
| Fit (contain) | Scales the image to fit inside the target box. Aspect ratio is preserved; if the source ratio doesn't match, the leftover area is padded with the background color. | Mixed-orientation libraries, catalog thumbnails where you can't crop, gallery uploads with a uniform frame. |
| Fill (cover, crop) | Scales until the image fully covers the box, then crops the overflow from the center. No padding, no distortion. | Hero images, profile pictures, social tiles — anywhere you want an edge-to-edge frame with no empty bars. |
| Stretch | Forces the exact width × height you typed, distorting the image if the source ratio doesn't match. | Fixed-size UI placeholders, mockups, sprite cells where exact pixel dimensions matter more than proportions. |
| Scale (%) | Each image is resized to a percentage of its own original dimensions. There is no shared target size. | Down-sampling a folder by 50%, generating @2x/@1x asset sets, reducing camera-resolution photos for the web while keeping each one's native shape. |
Common preset sizes
Social
- 1080 × 1080 Instagram square post
- 1080 × 1350 Instagram portrait
- 1080 × 1920 Stories / Reels
- 1500 × 500 X (Twitter) header
Display
- 1280 × 720 HD
- 1920 × 1080 Full HD
- 2560 × 1440 2K / QHD
- 3840 × 2160 4K UHD
Thumbnails & avatars
- 128 × 128 small avatar
- 256 × 256 thumbnail
- 512 × 512 profile photo
- 1200 × 630 OG / link preview
JPEG, PNG, or WEBP?
- JPEG. Smallest files for photographs. No transparency. Quality 80–90 looks identical to most eyes; 60–75 is fine for thumbnails. Use this for camera photos, product shots, anything photographic.
- PNG. Lossless and transparency-friendly, but files can be many times larger than JPEG. Use for logos, screenshots with text, line art, or any image with a transparent background you need to keep.
- WEBP. Modern format that beats both for size at the same visible quality and supports transparency. Use for web delivery where every browser your audience uses supports it (all evergreen browsers do).
- Keep original. The output for each file matches its input type. Handy when you just want to resize a mixed folder without changing formats.
Tips for clean output
- Don't enlarge. Upscaling never adds detail—it just blurs. Enable Don't enlarge when you want to cap images at a maximum size but leave smaller ones untouched.
- Padding background. In Fit mode, the leftover area around your image is filled with the background color you pick. Choose transparent when the output is PNG or WEBP and you want the empty area to show through.
- Quality slider. JPEG and WEBP support a quality setting; PNG ignores it because it's lossless. 92 is a good default for photos; drop to 80 for fast-loading thumbnails.
- Filename suffix. Resized files include the output dimensions in the name (for example
photo-1280x720.jpg), so they don't overwrite originals in the same folder.
Privacy
Every image is decoded, redrawn, re-encoded, and zipped entirely inside your browser using a local canvas and JSZip. No file is ever uploaded to a server. You can disconnect your internet after loading the page and the bulk resizer keeps working.