1Drop your images into the box above, or pick them from your device — there is nothing to install and no account to create.
2Choose how hard to squeeze: a quality or bitrate target, and optionally smaller dimensions if size matters more to you than detail.
3Start the job and let the workers re-pack the file; your original is never modified in place.
4Compare the new size against the original, then download the compressed Image file.
Compress Image FAQ
What do I get back, and can I control the trade-off?
+
A single compressed file per input, at a quality or bitrate level you choose rather than a fixed default. If the result is not small enough, changing the dimensions or the duration will do more than pushing the quality slider further down.
How does Compress Image actually make the file smaller?
+
Concretely, the right strategy is chosen per file — re-quantisation for a lossy source, stronger lossless packing for a lossless one — so a mixed batch does not get one blunt setting applied to everything. Nothing about it depends on you installing software: the job runs server-side and hands back a finished file.
Is there anything specific to Image I should know before compressing?
+
Yes — the pipeline reads the real format from the file header rather than the extension, so a mislabelled upload still works. It is worth knowing before you overwrite an original you might need again.
What is the most common mistake when compressing images?
+
Compressing the same file repeatedly. Each pass on a lossy format is a fresh generation of loss and the savings shrink while the damage accumulates. Go from the original to your target in one step, and keep the original.
Which image formats does Compress 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 Compress 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 Compress 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 Compress 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 Compress 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. Compress 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 Compress 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 Compress Image means the conversion is made from the version you settled on, not from the one you were still fixing.
Is Compress 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.
