What is the Batch Process tool?
This is the tool for the folder, not the file. Instead of opening twenty PDFs one after another and repeating the same three clicks in each, you drop the whole set in, choose one action, and let it run. You can batch process PDF files online here without installing a desktop suite or writing a script — it is a bulk PDF editor that lives in a browser tab.
Five actions are available from the Action menu: merge everything into one document, rotate every page, stamp a text watermark, add page numbers, or keep only certain pages. The important detail is that one setting applies to every file. If you pick 90° clockwise, all files rotate 90° clockwise. There are no per-file exceptions, which is precisely what makes a hundred files as quick as one.
Everything runs in JavaScript inside your own tab using pdf-lib, so the documents are never uploaded. That matters when the folder in question is a month of client invoices or a set of signed agreements — you get bulk convenience without shipping confidential material to somebody else's queue.
How to apply one change to many PDFs at once
- Drop your PDFs onto the drop area, or click it to browse. Add as many as you like; each one shows its page count and size in the list.
- Choose what to do from the Action menu — merge, rotate, watermark, page numbers, or keep only certain pages.
- Fill in the settings that appear for that action, for example the rotation angle, or the watermark text, size, opacity, angle and colour.
- Click any file in the list to preview the result for that file — the preview is built by the same transform that writes the output, so it cannot drift.
- Press Process all. Merging downloads one merged.pdf; every other action downloads batch-output.zip containing one processed PDF per input.
Key features
- Five bulk actions — merge all into one PDF, batch rotate PDF pages, bulk watermark PDF files, add page numbers, or keep only a page range from each document.
- Rotation that respects what is already there — 90°, 180° or 270° is added to each page's existing rotation, so a sideways scan ends up upright rather than reset to zero.
- Full watermark control — your own text, font size in points, opacity from 3% to 100%, an angle between −90° and 90°, and any colour, drawn centred on every page of every file.
- Page numbering options — six corner or centre positions, three formats (1, 1 / N, Page 1), a custom starting number and a margin in points.
- Per-file page ranges — type something like 1-3, 5, 8 and each document is trimmed to those pages individually; a file with fewer pages simply keeps what it has.
- Real preview, not a mock-up — selecting a file re-runs the actual transform on it and renders the resulting PDF, with the page count and output size underneath.
- One ZIP back — processed files are named after the original with a clear suffix such as -rotated, -watermarked, -numbered or -pages.
Benefits of using this bulk PDF editor
- Time saved scales with the pile. The setup effort is the same for three files or three hundred; only the processing time grows.
- Consistency by construction. Because one setting drives every file, the watermark sits in the same place and the numbering uses the same font across the entire set.
- Nothing is uploaded. No batch queue on a server, no retention policy to read, no job ID to worry about — the files are opened and rewritten locally.
- No quota and no watermark of ours. The only mark on your pages is the one you chose to add, and there is no daily file limit or signup wall.
- A tidy handoff. Getting one ZIP instead of forty loose downloads keeps your Downloads folder and your colleague's inbox sane.
Who should use this tool?
Agencies and studios
Client deliverables often need the same treatment before they go out: a DRAFT stamp across every page of every mock-up, or page numbers on a set of proposal exports. Set the watermark text, opacity and angle once, process the folder, and send a single ZIP.
Admin and back-office teams
Scanned paperwork tends to arrive rotated the wrong way in batches, because that is how it went through the feeder. Rotate the lot in one pass. When only the first two pages of each report matter, the page-range action trims the whole set to 1-2.
Legal and compliance staff
Bundles that must be numbered for reference, or marked CONFIDENTIAL before disclosure, are exactly this tool's job. Doing it locally also means the documents never travel to a third-party processor, which is usually the sticking point with online tools.
Teachers and course coordinators
Worksheets from several sources can be merged into one handout, or numbered so a class can follow along by page. Preview one file to confirm the position, then apply it to every worksheet at once.
Frequently asked questions
Can I use different settings for different files?
No — one action with one set of settings is applied to every file in the list. That is the trade-off that makes bulk work fast. If two groups need different treatment, process them as two batches.
How do I get the processed files back?
Merging produces a single merged.pdf. Every other action produces batch-output.zip with one PDF per input, named after the original plus a suffix such as -watermarked. Duplicate names get a number appended so nothing is overwritten.
How many PDFs can I process at once?
There is no hard cap; the limit is your device's memory, since every file is held in the tab while it works. Ordinary documents go dozens at a time comfortably. The live merge preview switches itself off above about 40 MB of input and asks you to press Process all instead.
Does the watermark go on top of the existing content?
Yes. The text is drawn over each page after the original content, centred and rotated by the angle you set. Keep the opacity low if the page underneath still has to be readable.
What happens if a file has fewer pages than my range?
It keeps whichever of those pages exist. Asking for 1-5 from a three-page document returns those three pages rather than failing, so a mixed folder still processes cleanly.
Can I batch process password-protected PDFs?
Encrypted files usually fail to open and will stop the run with an error. Remove the password first with the Unlock PDF tool, then add the unlocked copies to the batch.
Will processing many PDFs at once reduce their quality?
No. Pages are edited in place or copied between documents — nothing is rasterised or re-compressed, so text stays selectable and images keep their original resolution.
Does it work offline or on a phone?
Once the page has loaded you can disconnect and it keeps working, because the processing is local. It runs on phones and tablets too, though a big batch of heavy scans is happier on a laptop.
Related tools you might need
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