Image Resizer – Resize Up to 10 Images to Any Size
About the Image Resizer
The Image Resizer changes the pixel dimensions of up to 10 images in one batch, giving you three ways to specify the target: exact pixel values, a percentage scale, or a preset picked from social media, screen, and print dimension lists. Alongside that sits a Resize Mode control that decides what happens when your source aspect ratio does not match the target, which is the part most resizing tools get vague about and the part that determines whether your image ends up padded, cropped, or squashed.
The three modes are worth understanding before you start. Fit scales the image down until it sits entirely inside the target box, preserving the full frame. Fill scales up until the box is completely covered and crops the overflow evenly from both sides, which is what you want for a square Instagram post cut from a landscape photo. Stretch forces the exact dimensions regardless of proportion, distorting the image, and is only appropriate for textures or backgrounds where distortion is not visible.
Everything runs client-side through the Canvas API with high-quality image smoothing enabled, so no file is uploaded and there is no processing queue. The uploader accepts any format your browser can display, including JPG, PNG, WebP, GIF, AVIF, TIFF, and BMP, and decodes iPhone HEIC and HEIF photos first. Output is written as JPEG, PNG, or WebP, with a quality slider that applies to the two lossy options.
The preset list covers the sizes people actually search for: Instagram posts and stories, Facebook and LinkedIn link images, YouTube thumbnails, Pinterest pins, standard screen resolutions from VGA up to 4K, and print sizes calculated at 300 DPI. If your goal is smaller files rather than specific dimensions, the Image Compressor approaches the same batch from the quality side with per-file savings totals.
Everyone at BigToolSite who worked on this tool tested it against portrait and landscape sources in all three modes, verified that Fill crops symmetrically rather than from one edge, checked that percentage scaling above 100% enlarges correctly, and confirmed that transparent PNGs keep their alpha channel unless JPEG output is selected.
Photographers starting from iPhone files usually need a format change before anything else, and the HEIC Image Converter handles that step with a wider set of output options.
If you are producing a single favicon or app icon rather than a batch, the ICO Image Converter works with icon containers directly and extracts specific embedded sizes.
How to Use the Image Resizer
- Drag 1 to 10 images onto the upload area or click to browse and multi-select. Each file can be up to 10MB.
- Each image appears as a row with a thumbnail, filename, current dimensions, source format, and file size.
- Choose a Resize By method: Custom Pixels for exact width and height values, Percentage for a scale between 10% and 300%, or Preset Sizes for a named dimension from the dropdown.
- In Custom Pixels mode, enter width and height, and leave Maintain aspect ratio checked so the image fits inside those dimensions without distortion. Uncheck it to use the Resize Mode control instead.
- Pick a Resize Mode: Fit to scale the whole image inside the box, Fill to cover the box and crop the excess, or Stretch to force exact dimensions.
- Select an Output Format: JPEG, PNG, or WebP.
- Set the Quality slider between 10% and 100%. The default is 85%, and it affects JPEG and WebP output only.
- Click Resize All. Each row fills a progress bar, then shows the original dimensions struck through next to the new dimensions in green.
- Download individual files, or use Download All (ZIP) for the whole batch. Filenames include the new dimensions, for example photo-1080×1080.jpg.
- Change any setting and click Resize All again to reprocess, or use Remove and Clear All to reset.
Example Usage
Input: 5 landscape photos, 4032×3024 each
Settings: Resize By Preset, Instagram Post (1080×1080), Mode Fill, Format JPEG, Quality 85%
Result: each photo scaled up to cover 1080×1080 and cropped evenly on the left and right, downloaded as photo-1080×1080.jpg
Switching the same batch to Fit instead produces images that keep the full landscape frame, scaled down to 1080×810 with no cropping. The Fit calculation returns the scaled dimensions rather than a padded square, so you get a clean 4:3 image rather than white bars.
For a blog where you only need everything at half its current size, choose Percentage and set the slider to 50%. Aspect ratio is always preserved in percentage mode and Resize Mode is ignored, so a 4032×3024 photo becomes 2016×1512 and a 1200×800 graphic becomes 600×400 in the same run.
Percentage mode also goes up to 300%, which enlarges rather than shrinks. Enlarging cannot add detail that was never captured, so use it for line art, logos, and screenshots rather than for photographs, where upscaling produces visible softness.
Frequently Asked Questions
Fit scales the image down until it sits entirely within your target dimensions, keeping the whole frame. Fill scales it up to cover the target completely and crops the overflow evenly from both sides. Stretch forces the exact dimensions and distorts the image if the aspect ratio does not match.
Use Fit or Fill rather than Stretch, or leave Maintain aspect ratio checked in Custom Pixels mode. Percentage mode always preserves proportions automatically.
Up to 10 per batch, with each file capped at 10MB. All of them use the same settings, so this works best when your sources are similar in orientation.
No. Decoding, resizing, and encoding all happen locally in your browser through the Canvas API, so your files stay on your device.
1080×1080 pixels for a square post and 1080×1920 for a story or Reel. Both are available in the Social Media section of the preset dropdown, along with sizes for Facebook, X, LinkedIn, Pinterest, and YouTube thumbnails.
Yes, using Percentage mode up to 300% or by entering pixel values above the original. Enlarging cannot recover detail that was not in the source, so results are softer on photographs than on graphics and text.
Usually yes, since fewer pixels means less data. The summary strip shows the exact percentage change across the batch, and the quality slider gives you additional control over JPEG and WebP output.
Yes, if you choose PNG or WebP as the output format. JPEG has no alpha channel, so transparent areas are filled with white.
They are calculated at 300 DPI, the standard resolution for photo printing. A 6×4 inch print needs 1800×1200 pixels, an 8×6 needs 2400×1800, and so on up to 17×12 inch.
