How to Add Page Numbers to a PDF

Provide a valid PDF as strict Base64-encoded data, choose a supported position and starting number, then apply a page-number format such as {page}. A successful run produces modified PDF data with the numbers applied.

What this PDF page numbering tool does

PDF Page Numbers adds numbered text to a PDF and lets you choose where that text appears, which number to start with, and how the number is formatted. It is useful for reports, contracts, drafts, and other documents that need page references before sharing or printing.

The input must be strict Base64-encoded PDF data. After decoding, the data must begin with the PDF signature. The tool provides six placement choices: bottom-left, bottom-center, bottom-right, top-left, top-center, and top-right.

Step-by-step instructions

1. Prepare the PDF as strict Base64-encoded data. Check that the decoded data is a valid PDF whose bytes begin with the PDF signature.
2. Provide the encoded PDF as the file input.
3. Choose a page-number position. If you leave this setting unchanged, the number is placed at the bottom center. Use one of the supported positions rather than inventing a custom placement value.
4. Set the starting number if the document should begin with a value other than 1. The default is 1, and later pages use increasing numbers from that starting value.
5. Enter the text format for the inserted number. The default format is {page}, where the page-number value is inserted. Keep the resulting formatted text at 100 characters or fewer.
6. Start processing and save the resulting PDF data when processing succeeds.

How to read the result

A successful result is modified PDF data with page numbers applied. The placement corresponds to the selected supported position, while an unchanged position setting places the numbers at the bottom center. The first number follows the supplied starting value, and subsequent pages increase from it.

The format controls the inserted text. For example, a format such as Page {page} creates text containing the page number in that pattern, subject to the 100-character limit. A failure can indicate that the encoded input is not valid PDF data, that a position is outside the supported set, that the starting-number value cannot be converted appropriately, or that the formatted text is too long. The tool does not establish whether a document is stored, processed locally, or requires an account.

Worked example

You are preparing a report whose printed pages should show labels such as Page 5 at the bottom right.

Provide the report as strict Base64-encoded PDF data, choose bottom-right, set the starting number to 5, and use Page {page} as the format.

The successful result is modified PDF data in which the pages contain bottom-right labels beginning with Page 5, followed by increasing page numbers on later pages.

Limitations

• Processing can fail when formatted page-number text exceeds 100 characters, decoded input lacks the PDF signature, or a position is outside the six supported choices.

Common errors

• A frequent input mistake is providing ordinary text or non-PDF Base64 data. Convert the actual PDF bytes to strict Base64 and verify that the decoded data begins with the PDF signature before trying again.

FAQ

Can I add page numbers to any PDF file?

Yes, when the input is valid strict Base64-encoded PDF data and the selected settings pass validation. The decoded data must begin with the PDF signature, and the formatted page-number text must not exceed 100 characters.

Where can the page number appear?

The default is bottom-center. You can instead select bottom-left, bottom-right, top-left, top-center, or top-right.

Can numbering start at a number other than 1?

The starting number defaults to 1. Set another compatible starting value when needed; subsequent pages use increasing numbers from that value.