1Upload the JPG images you want to mark, already at their final size — watermarking comes after resizing, not before it.
2Upload a transparent PNG logo or type your text, then choose the font, the colour and the opacity.
3Set the position, or switch to a tiled repeat when a single corner mark would be too easy to crop away.
4Download the watermarked JPG file; nothing else is added to it.
Watermark JPG FAQ
Should I watermark before or after resizing?
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After. Watermark the final deliverable at its final size, so the mark stays legible and proportionate. Watermarking a master you will process again means the mark gets resampled and compressed along with everything else.
How does Watermark JPG place the mark?
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Concretely, the mark is composited onto the decoded image and the result is re-encoded once, so add the watermark last, after any resizing or compression, rather than watermarking a master you will process again. You control the position, the size and the opacity, and the same settings are applied consistently across everything you upload.
Anything specific to JPG worth knowing?
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Yes — every save re-runs the quantiser, so repeatedly editing and resaving a JPG compounds generation loss even if you never lower the quality slider. It affects when in your workflow the mark should be applied.
Does a watermark actually protect my work?
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It deters casual reuse and it credits you; it is not security. A corner mark can be cropped and a faint one can be painted out. If protection matters, a large semi-transparent mark across the subject is far harder to remove than a discreet one in a corner.
What can I upload to Watermark JPG?
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Anything in the lossy raster family — JPG, JPEG, JFIF and WebP — plus the lossless formats (PNG, BMP, TIFF) if you want to mix them in one batch. The format is read from the file header, not the extension, so a photo saved with the wrong suffix still goes through.
Is there a file size limit on Watermark JPG?
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Yes: free accounts process images up to 25 MB each, which covers essentially every camera JPG and phone photo; the work is done by libjpeg-turbo and libwebp, the same libraries a desktop editor links against. Larger files are the one thing the free tier will stop you on, and the limit is per file rather than per batch.
Will Watermark JPG lower the quality of my JPG images?
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A lossy source is already the result of one quantisation pass, and any operation that has to re-encode adds a second. Where the job can be done without touching the pixel data we do that instead, and where it cannot you choose the quality factor yourself rather than getting a fixed default.
Can I run Watermark JPG on several JPG images at once?
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Yes. Drop the whole set into the upload area and they queue in parallel with identical settings — that is the main reason to do this in a browser rather than one file at a time in an editor. Free accounts run one file per batch; a pass lifts that.
Why does a EPUB site host Watermark JPG?
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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. Watermark JPG 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 Watermark JPG is finished?
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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 Watermark JPG means the conversion is made from the version you settled on, not from the one you were still fixing.
Is Watermark JPG here the same tool the sibling sites run?
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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?
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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.
