PDF merge sites that ask you to upload A3 scans of a house are asking you to trust their disk. Construction drawings, passports in an appendix, and fee numbers do not belong there. ToolsGuru’s PDF tools rewrite files in the browser with pdf-lib. This guide follows one packet from a real-shaped job: a riverside house extension, a procurement email that allowed one attachment, and a client portal that rejected files over 5 MB.
The packet: portrait proposal + landscape register
The fee proposal was three A4 portrait pages from Word, exported to PDF. The drawing register was twelve landscape pages from a CAD export, already PDF. The joiner’s rule is concatenation, not imposition: you stack pages. Drop proposal.pdf first, then register.pdf. Drag if the order is wrong. Download `packet-riverside-extension.pdf`.
Open the result and scroll. Landscape pages should stay landscape. If a viewer auto-rotates, check another viewer before you rotate ‘to fix’ it — you may be fighting a flag. Use the page rotator only when a scan is genuinely sideways.
When the portal says 5 MB and your packet is 18 MB
Scanned drawings are heavy. Merging does not magically compress them. Options: (1) split out the two drawings the planner actually asked for using the splitter (`12-13` or whatever the page numbers are in the merged file — count after merge, not in the CAD export); (2) if the scans are image-only, export those pages to images, compress, and rebuild with Images to PDF — knowing you may lose vector snap lines; (3) ask the portal for a file-drop exception. Do not downsample structural drawings until they are unreadable just to beat a widget.
The splitter used page ranges, not ‘every page as its own email’. The contractor who only needed the damp-relevant sheets should not receive the fee page with the day rate.
Signatures and certificates
Rewriting a PDF to merge, split, watermark, or delete pages typically invalidates certification signatures. If a document is digitally signed and must stay verifiable, do not run it through a rewriter. Send it as-is or use a signing workflow the recipient recognises.
Delete, watermark, metadata — the hygiene pass
Blank scanner pages: page deleter. Draft in flight: watermark `DRAFT — 17 Sep 2026` at low opacity so a governor does not treat it as adopted policy. Author field still showing your laptop login: metadata viewer, then clear. Clearing Title/Author is not a full forensic wipe; XMP and attachments can remain. For a public upload of a ‘neutral’ briefing, it is still worth doing.
Covering a National Insurance number with a white box in the editor is not redaction. Flatten to images or use a redaction tool if the file leaves your control.
A note on Word-to-PDF
If the proposal started as .docx, the PDF converter’s layout is best-effort. Text boxes and tracked changes misbehave. For a fee letter, export from Word/LibreOffice to PDF on the authoring machine when you can, then only merge here. Use in-browser conversion when the machine in front of you cannot install Word.
Tools used in this guide
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Written by the ToolsGuru operators. No guest-post network, no scraped competitor pages. Corrections: contact@toolsguru.net.