1Upload the images you want resized — work from the largest original you have rather than from a copy you already shrank once.
2Type a target width, a target height or a percentage, and leave the aspect-ratio lock on unless you deliberately want stretching.
3Run the resize; every file in the batch is taken to the same target in a single pass.
4Download the resized Image file, or the whole set together as one archive.
Resize Image FAQ
How does Resize Image change the dimensions?
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Concretely, each file is resampled with Lanczos and written back in its own format, so a mixed batch comes out consistently sized without being forced through one common format first. You give it a target width, a target height or a percentage, and it works from the original rather than from a previously resized copy.
Can I keep the aspect ratio, or force exact dimensions?
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Both. Lock the ratio and one dimension is derived from the other, which is what you want almost always. Unlock it and you get exactly the numbers you typed, at the cost of stretching — useful for a fixed slot, wrong for a photograph.
Does the source format affect the result of a resize?
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It does. this format is read and written by the same streaming pipeline as everything else we support. That is what decides whether shrinking the file is purely a question of pixels or also a question of re-encoding.
Is there anything specific to Image I should watch for?
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Yes — the pipeline reads the real format from the file header rather than the extension, so a mislabelled upload still works. Worth checking before you resize a file you will not be able to regenerate.
What is the most common mistake when resizing images?
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Upscaling. Enlarging cannot invent detail that was never captured, so the result is a soft version of the original at a bigger size. Always resize down from the largest source you have, and resize once rather than in stages.
What dimensions should I actually target?
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Match the slot it will live in. A full-width web hero rarely needs more than 1920 pixels wide, a content image 1200, a thumbnail 400, and doubling those numbers covers high-DPI screens. Anything beyond that is bytes nobody sees.
Which image formats does Resize Image accept?
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All of the common ones — JPG, JPEG, PNG, WebP, GIF, BMP, TIFF, SVG, ICO, PSD, JFIF and HEIC. You can mix formats freely in one batch; each file is identified from its header and routed to the right decoder.
Is there a file size limit on Resize Image?
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Yes: free accounts process images up to 25 MB each regardless of which image format you brought; ImageMagick, libjpeg-turbo, libpng and libwebp do the actual work. The cap is per file, so a batch of twenty 5 MB photos is fine even though the total is well over the limit.
Will Resize Image lower the quality of my images?
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That depends on what you brought. A lossless source (PNG, BMP, TIFF) round-trips exactly; a lossy one (JPG, WebP, GIF) is already the product of one quantisation pass and only re-encodes if the operation genuinely requires it.
Can I run Resize Image on several images at once?
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Yes, and mixing formats in the batch is fine — settings are applied per file with the right decoder for each. Free accounts run one file at a time; a pass removes that.
What happens to metadata and transparency?
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EXIF and the ICC colour profile are carried across wherever the target format supports them, and an alpha channel survives into any format that has one. Transparency is only flattened when the destination format has no way to represent it.
Does Resize Image cost anything?
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No. Resize Image is free without an account and adds no watermark. Uploads are deleted from the workers shortly after the job completes.
