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If the file cannot leave your machine, the only option is a tool that does the work inside the browser tab. Use the Bates Numbering tool here: pick the PDFs, set the prefix and starting number, and the numbering runs on your computer. Nothing is sent to a server, so there is no upload log and no third-party copy of the client file.
Everything below is about that constraint. It explains what browser-local processing actually guarantees, where it stops, and how to check a result before it goes out the door.
What “browser-local” actually means
When a file tool runs locally, the page loads a script (often WebAssembly) that reads the file from your disk into the browser’s memory. The processing happens on your CPU. The finished file is written back to your downloads folder. The network tab stays quiet during the work.
That is a different model from an online converter, where you attach the file, it travels to a server, and a link comes back. In that model the file exists on someone else’s disk, however briefly, and you rely on their retention policy. For a contract under NDA, a medical record, or an HR file with salaries in it, that difference is the whole point.
Browser-local also means no account. There is nothing to sign up for, no dashboard holding your documents, and no sync that quietly copies them somewhere. Close the tab and the working memory is gone.
What it does not mean is that the machine is safe. If the computer is compromised, or the browser is running an extension with permission to read pages, local processing will not save you. For a high-sensitivity set, work in a clean browser profile with extensions disabled and check the result before sending.
Where local processing stops working
Local processing is bounded by the machine it runs on. A few practical limits:
| Constraint | Typical threshold | What happens past it |
|---|---|---|
| Browser tab memory | roughly 1 to 2 GB of file data, lower on 32-bit or older machines | tab slows, then crashes; work is lost |
| Very large single PDFs | hundreds of megabytes of scanned pages | page rendering stalls between files |
| Encrypted PDFs | password-protected files | tool cannot read pages until the password is removed |
| Scanned PDFs without OCR | image-only pages | numbering still applies, but there is no text layer to search |
| Mobile browsers | smaller memory budget | large sets may fail on phones and tablets |
| Numbering consistency | your own prefix and digit width | a mismatch in width breaks sort order later |
None of these is a reason to upload instead. They are reasons to split a big set into batches and to check the plan before you start numbering.
Check the set before you number it
Numbering is hard to undo once the files are produced and sent. Do this first:
- Decide the prefix. Usually a party code or case code, kept short and consistent, for example
ABC-. - Decide the digit width. Six digits (
000001) is a common default; pick a width and keep it for the whole set so files sort correctly. - Decide where the number sits. Bottom right is typical for production. Confirm the placement does not cover signature lines, footers, or page numbers already on the page.
- Confirm the starting number. If this set continues from an earlier production, start from the last number used plus one.
- Put the files in order. Alphabetical by filename is fine only if the filenames already reflect the intended order. Otherwise rename them first, because the numbering follows the order you hand the tool.
If you need to change the order of the pages themselves, do that before numbering. Use Merge PDF to join files or reorder pages into one document, then number the combined set so the sequence stays continuous.
Work in batches, keep the numbers continuous
For a small set, one pass is enough. For a large one, split it:
- Batch 1 starts at the beginning number. Note the last number it produced.
- Batch 2 starts at that last number plus one. Do not restart from one.
- Keep the batch list on paper or in a separate note, not inside the PDFs.
This is also how you recover from a crash. If the tab dies halfway, the completed files are already in your downloads folder. Number the remainder only, starting after the last number you actually got.
Check the output before it leaves the machine
A numbering run can fail quietly. Before the set goes out:
- Open the first and last file of each batch and read the stamp on the page.
- Check that the digit width did not change mid-set (a
000099followed by0000100will break sort order). - Check that the stamp does not cover existing content.
- Search the PDF for the last number you expect; if it is not on the last page, the run stopped early.
If the files were scanned and you need them to be searchable as well as numbered, run OCR in a desktop editor first. The numbering tool does not add a text layer.
When this does not apply
Browser-local numbering is the wrong approach in a few cases, and it is better to know now:
- The set is large enough that the browser cannot hold it. A set in the gigabytes usually belongs in a desktop editor or a document management system, where batch processing is designed for it.
- The files must be produced with a specific load file or metadata format that the recipient requires. That format is set by the receiving system, not by the numbering tool.
- Multiple people need to work on the same set at the same time. Local processing is single-machine by definition; concurrent work needs a shared system with access control.
- The page placement must be exact, such as a stamp in a fixed position relative to a header on every page. Check the tool’s placement options against the requirement before starting, not after.
The work is a document-preparation task, not a legal one. Deciding what must be produced, in what order, and with what numbering is a question for the person running the matter; this page covers only how to get the numbers onto the pages without the files leaving the machine.
If you are already handling other file-prep steps, the same local-processing rule applies to Images to PDF, which assembles scanned pages without sending them out. And when you are working with a spreadsheet or a list of file names that has to stay on the machine, JSON Formatter runs locally too, so structured lists do not travel to a server either.
FAQ
how do i add bates numbers without uploading the pdf
Open the Bates numbering tool in your browser, select the PDFs from your disk, set the prefix and starting number, and run it. The numbering happens in the tab and the stamped files save to your downloads folder. Nothing is sent to a server.
is bates numbering in the browser safe for client files
The file is read into the browser’s memory and processed on your machine, not uploaded. For sensitive sets, use a clean browser profile with extensions disabled and confirm the output before sending.
what is the starting bates number if i am continuing a set
Start at the last number used in the previous production plus one, and keep the same digit width and prefix so the combined set sorts correctly.
why do my bates numbers jump or restart in the middle
Most often the set was split into batches and a later batch restarted from one, or the digit width changed so a number like 000099 is followed by 0000100. Check the last number of each batch before starting the next.