After you add a header and footer to a PDF using the Header Footer PDF tool, the way to check the result is to open the new file the tool downloads and scan every page in any standard PDF reader. The downloaded file keeps your original filename base and adds -header-footer.pdf, while the source document you loaded stays exactly as it was. Inside the new file, one optional header line sits below the top edge and one optional footer line sits above the bottom edge, both horizontally centered using the embedded standard Helvetica font, on every structural page of the original document. The tool draws the lines as additional content inside the existing page boxes, so the only way to confirm placement, sizing, token replacement, and centering is to open the resulting file and visually inspect each page. This verification step matters because the tool does not move body content, create white space, or detect logos and crop marks, so existing content near an edge can overlap the new line.
What the Output Should Look Like
When the tool finishes, the browser saves a new PDF next to your downloads. The filename base stays the same as the source, with -header-footer.pdf appended, so a file called report.pdf becomes report-header-footer.pdf. The original PDF you selected is not modified, and the page order, page count, and existing visible content are preserved. Each page of the original receives one optional header line and one optional footer line, both drawn inside the existing page box.
If you entered a header, it sits below the top edge by your chosen margin plus your font size, and if you entered a footer, it begins above the bottom edge by your chosen margin. Both lines are horizontally centered based on the actual width of the text after the embedded standard Helvetica font measures it, not on a fixed character count. The {page} token is replaced with the one-based current page number, and {pages} is replaced with the total structural page count of the source. A footer such as Page {page} of {pages} therefore becomes Page 2 of 5 on the second page of a five-page document.
How to Inspect the New PDF
- Locate the downloaded file. The file is saved with the same name as your source plus -header-footer.pdf, so look for that filename in your browser's download list or your Downloads folder.
- Open the file in any PDF reader. Double-click the file or right-click and choose Open with, then pick the reader you normally use, such as Adobe Acrobat, Preview, Foxit, or a browser tab.
- Jump to the first page. Look at the top edge for your header text and the bottom edge for your footer text, and confirm both are horizontally centered.
- Use the reader's page navigation to move to the last page. Confirm the footer shows the highest page number and that the {pages} token resolved to the correct total.
- Spot-check three pages in the middle. The header and footer should appear on every structural page with the same text, same font size, and same horizontal position.
- Zoom in to verify text rendering. If a glyph looks like a box or a question mark, the embedded standard Helvetica font cannot encode that character, and file creation should have failed visibly instead of producing a PDF with missing glyphs.
- Compare with the source. Open the original PDF alongside the new one to confirm that page order, page count, and existing visible content are unchanged.
Verifying Tokens, Margins, and Centering
The table below maps each verification check to the behavior the tool guarantees, so you can compare what you see in the PDF reader with what the tool actually does on every structural page.
| Check | What to look for | What the tool guarantees |
|---|---|---|
| Page-number token | Each page shows the correct one-based page number | {page} is replaced deterministically on every structural page |
| Total page token | Total matches the source page count | {pages} reflects the structural page count of the source |
| Font size | Text matches the whole value you entered | Accepts whole values from 6 to 36 points |
| Edge margin | Distance from edge matches the value you entered | Accepts whole values from 0 to 200 points |
| Centered alignment | Text sits in the horizontal middle of the page | Centered from the real text width measured with embedded standard Helvetica |
| Header position | Below the top edge by margin plus font size | Drawn below the top edge by the selected margin and font size |
| Footer position | Above the bottom edge by margin | Begins above the bottom edge by the selected margin |
| Width limit | If text is too wide, font shrinks to 6 points | Reduces one point at a time to a 6-point floor, never wraps or deletes |
| Text length | No more than 120 characters per field | Each text field is trimmed and limited to 120 Unicode characters |
What to Do If the Result Is Not Right
Several common issues are visible the moment you open the downloaded file.
If the header or footer overlaps body content, the tool draws inside the existing page box and does not push body content down or create white space. To fix overlap, return to the tool, lower the font size, increase the edge margin, or move body content in the source PDF before re-running the tool. The guide Does a Header Footer PDF Tool Make Room for the Text? explains this behavior in more detail.
If a line looks smaller than the size you requested, the entered text was too wide for the page and the tool shrank it one point at a time down to a 6-point floor. Shorten the text, lower the font size yourself, or reduce the edge margin to widen the usable area on every page.
If a line is missing on some pages, the most likely cause is a glyph that the embedded standard Helvetica cannot encode. File creation should have failed visibly in that case, but if a partial file is on disk, re-check the entered text for characters outside the standard Latin set and remove emoji or unsupported scripts before running the tool again.
If the download filename matches a previous run, any change in source file, header text, footer text, font size, or margin revokes the previous download and produces a new one, so a stale file from an earlier session cannot be mistaken for the current configuration when you inspect the result.
How the New PDF Is Built
Knowing the construction order helps you predict the verification result before you open the file.
The browser loads the source PDF locally, validates it as a non-empty PDF no larger than 25 MiB, and trims each text field to 120 Unicode characters. It expands {page} and {pages} deterministically for every structural page, then embeds standard Helvetica once. The tool measures each line with the embedded font, and if the line is wider than the usable page width at the requested font size, the tool reduces the size one point at a time down to a 6-point floor without wrapping or removing text. It centers each line within the existing page box using the measured text width, places the header below the top edge by the margin and font size, places the footer above the bottom edge by the margin, and serializes a new PDF. The pdf-lib PDFPage drawText method handles the placement, and the standard Helvetica font comes from the pdf-lib StandardFonts enum.
Why the Result Varies by Document
Three inputs change what you see in the verified result: the source page dimensions, the chosen margin, and the chosen font size.
Wider pages give the centered text more horizontal room before shrinking kicks in, while very narrow pages can force the tool to drop to the 6-point floor even for short strings. Larger margins reduce the usable space and can trigger shrinking or make lines look crowded against body content. Higher font sizes widen each character and shorten how much text fits, so a 36-point header covers more horizontal space than a 6-point header at the same margin.
The relationship between these three inputs is straightforward: usable text width equals page width minus two times the edge margin. Any text whose measured width exceeds that usable width triggers the shrinking rule. The exact pixel measurements depend on your specific PDF, so run the tool and inspect the output to confirm the placement looks right before sharing or printing.