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
What dimensions should I actually target?
+
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.
How does Resize Image change the dimensions?
+
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.
Is there anything specific to Image I should watch for?
+
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?
+
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.
Which image formats does Resize Image accept?
+
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?
+
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?
+
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?
+
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.
Why does a EPUB site host Resize Image?
+
EPUB.to is built around the open eBook format — XHTML in a zip, reflowable by design, and readable on hardware nobody has thought about the layout for. A book is a zip full of markup, images and fonts, so almost every job people bring to an eBook site is really a job on one of those things. Resize Image runs on the same upload and the same account as the conversions because that is where it is needed.
What should I do with the result once Resize Image is finished?
+
The converter on this site moves books between EPUB, MOBI, AZW3, PDF and DOCX, so a title ends up on whatever hardware is actually going to read it. Doing that after Resize Image means the conversion is made from the version you settled on, not from the one you were still fixing.
Is Resize Image here the same tool the sibling sites run?
+
The engines are shared — the same toolchain, the same workers, the same limits. What a EPUB site adds is a view on reflow: which of these operations a reflowable book genuinely supports, and which ones only make sense on the fixed-layout media inside it. It also starts from one fact about the format this site is named after: the book is a zip of XHTML with a manifest, so the text costs almost nothing and every decision that matters is about the embedded images and font subsets.
Do I need an account, and does anything get kept?
+
No account, and nothing is kept: uploads are deleted from the workers shortly after the job finishes, nothing is read and nothing is indexed. Free accounts exist for history and batch size, not for access.
