Add Watermark to PDF

Click Upload PDF, choose your .pdf file (single file or up to 5 queued files), then open the Add Watermark panel and switch to Text. Type your text, pick a font (Arial, Times New Roman, Calibri, Roboto or Open Sans), set font size (6–200 pt) and opacity (0–100%) using the slider, then choose Position (Center, Top-left, Top-right, Bottom-left, Bottom-right) or enter X/Y offsets in mm. Use Rotation (−180 to 180°) and Scale (10–400%) to adjust appearance, enable Tile if you want repeated text across the page, then click Apply to All Pages or Apply to Selected Pages and press Download to get original_name_watermarked.pdf.

Yes — choose Upload PDF, open Add Watermark and switch to Image, then upload a PNG, JPG/JPEG, WebP, GIF, BMP or TIFF as your logo; Safari/iOS will convert HEIC to JPEG on selection, so upload HEIC only after converting to JPG if you need transparency. Individual watermark images must be under 10 MB; for best results use PNG with transparency and a resolution around 300–1200 px on the longest side. After upload you can set opacity (0–100%), rotation (−180 to 180°), scale (10–400%) and choose Keep Aspect Ratio or Stretch, then Apply and Download.

Each PDF upload is limited to 50 MB per file for desktop Chrome/Firefox and typically up to 25 MB on mobile browsers; you can queue up to 5 PDFs per session using Add another file, each processed individually. Page count practical limit is about 1000 pages — larger documents may cause browser memory errors (Out of Memory) especially in Safari or on low-RAM devices; if you need to process longer files, split the PDF into smaller parts (100–300 pages) or use a desktop tool. Watermark images are limited to 10 MB; if a job fails, reduce image resolution or split the PDF and retry.

Open your PDF, go to Add Watermark and either type CONFIDENTIAL or choose a Stamp Preset from the dropdown (Confidential, Draft, Sample, Internal Use Only). Select preset style, choose font and size (recommended 48–120 pt for center stamps), set opacity to 20–60% for a translucent stamp, then use Rotation (e.g., −45°) and Position Center to get a diagonal stamp look. Click Apply to All Pages to stamp every page; the tool does not add its own watermark and the resulting file downloads as original_name_watermarked.pdf.

The tool is free to use in the browser with no signup required and it does not add a proprietary watermark to your output PDF — the downloaded file will be just your document plus the watermark(s) you added. There are no hidden accounts; however preset/save features do not persist across sessions because there is no user account. If you need automated server-side batch processing or long-term preset storage, consider a paid desktop or server solution; this tool is intended for quick, single-session edits.

Opacity is controlled by a slider and numeric input allowing 0–100% in 1% increments; rotation accepts any integer from −180 to 180 degrees with live preview. Position offers presets (Center, Top-left, Top-right, Bottom-left, Bottom-right), plus numeric X/Y offset fields in millimetres for precise placement, and a Tile option with horizontal/vertical spacing in mm. Scale is a percentage between 10–400% with Keep Aspect Ratio toggle; all changes update the on-screen preview before you Apply and download.

By default the tool optimises output for smaller downloads by recompressing embedded images to roughly 150 DPI which often reduces file size by 30–70%; there is an option named Keep original PDF quality you can toggle before applying if you prefer no recompression (this produces larger files). Choosing Keep original preserves image resolution and color profiles but can produce downloads that are several times bigger, so uncheck it for faster downloads and smaller files. If you notice visible banding or downsampling artifacts, re-upload with Keep original enabled or use a desktop app to control image compression more precisely.

Unsupported file errors happen when you try to upload non-PDFs for the main document (only .pdf accepted) or an image format the browser blocks; for watermark images ensure you use PNG/JPG/WebP/GIF/BMP/TIFF and keep the image under 10 MB. 'Image too large' is resolved by resizing the logo to ~1200 px on longest side or saving as PNG-8/JPEG with quality 70–85 in an editor; if you hit browser memory errors on very large PDFs reduce page count or use Chrome on desktop with at least 8 GB RAM. Also disable aggressive browser extensions or ad blockers that may block the upload script if uploads fail.

Yes — after setting up your watermark, use the Page Range field and enter ranges like 1-3,5,7- to target specific pages; the tool accepts comma-separated lists and open-ended ranges. There's also a checkbox Apply to All Pages for a one-click full document stamp; when applying to ranges you can preview the first targeted page before finalising to ensure placement is correct. If your PDF has mixed orientation spread, set Position and Rotation for each orientation by previewing odd/even pages and optionally run two quick jobs for complex layouts.

On desktop Chrome and Firefox you get drag-and-drop, multi-file queueing and larger per-file limits (50 MB); on mobile (iOS/Android) drag-and-drop is not supported, file input may convert HEIC to JPEG (iOS) and available RAM is lower which can cause timeouts on PDFs over ~200 pages. Safari on iOS sometimes opens the result in a new tab instead of downloading — long-press the PDF preview and choose Download to save to Files. For large or many files use a desktop browser (Chrome recommended) to avoid memory/time issues and to enable queuing and drag-and-drop.

Files are processed client-side in your browser when possible, so the document data does not leave your machine in normal use; a small server-side fallback may be used for very large files or incompatible browsers, in which case temporary uploads are retained on the server for up to 24 hours for processing and are deleted automatically. There is no account storage and no persistent retention; if server processing is used you will see an explicit notice before upload. For highly sensitive documents, use an offline desktop tool (Adobe Acrobat Pro, PDFtk) to guarantee zero network transfer.

Watermark PDF Online is fast for single-session jobs: add text or image stamps, set opacity/rotation/scale, and download without signup; it’s best for moderate-size PDFs (under 50 MB, under 1000 pages) and quick edits. Adobe Acrobat Pro provides advanced PDF features like flattening layers, PDF/X export, redaction workflows, and scripted batch jobs that preserve metadata and color-managed output for print; Photoshop opens pages as raster images which is better for pixel-level editing but will rasterize vector content. Use Watermark PDF Online for quick, no-install tasks and switch to Acrobat/Photoshop when you need enterprise batching, precise print color control, or retention of complex PDF structure.