PDF guides
Practical, step-by-step answers to everyday PDF problems — getting files under upload limits, signing, passwords, scanning and printing — written by the team that builds PDFora's tools.
A4 vs US Letter: printing PDFs without clipped edges
A4 (210 × 297 mm, 595 × 842 points) is 5.9 mm narrower and 17.6 mm taller than US Letter (8.5 × 11 in, 612 × 792 points), so printing one on the other at actual size clips edges, and fitting it adds white bands. The reliable fix is to convert the PDF to the recipient's size before you send it, then check the edges.
· 9 min readAre online PDF tools safe? How to check where your file goes
Some online PDF tools upload your file to a server; others process it inside your browser so it never leaves your device. You can see which in a few minutes with the browser's Network tab, and for IDs, medical and financial files you should prefer local processing and strip metadata, comments and editable fields before sharing.
· 8 min readBates Numbering: Prefixes, Sequences and Stamping PDFs
A Bates number is a prefix plus a zero-padded running number, such as ABC-000001, that gives every page in a document set its own reference. Choose the prefix and digit count before you start, give each new file a start number one higher than the last label on the file before it, and log every range in an index spreadsheet. This is general information, not legal advice; your court's or regulator's rules come first.
· 8 min readHow to Combine Scans, Photos and Word Files into One PDF
Convert photos and Word files to PDF first, give every file a two-digit prefix in the order the organisation wants, then merge and fix individual pages in Organize Pages. Resize everything to A4 if sizes are mixed, compress only if the file is over the limit, and add page numbers and bookmarks last, because merging, resizing and compressing all remove bookmarks.
· 7 min readHow to Extract Text from a Scanned PDF Accurately
If a PDF has a text layer, PDF to Text copies it exactly; if it is a scan, you need OCR. Rotate, deskew and crop the scan first, pick the right language, then choose a searchable PDF for keeping or a .txt file for reuse. Always proofread numbers, because OCR confuses look-alike characters: a 7 read as a 1, or the letter O read as a zero.
· 7 min readPDF Passwords Explained: Open vs Permissions, AES-256 and Limits
A PDF open password encrypts the file so nobody can read it without the password; a permissions password only asks reader apps to block printing, copying or editing, and many apps can ignore it. With AES-256 the weak point is the password itself, so use a long random one, send it separately from the file, and keep an unprotected original, because a forgotten open password cannot be recovered.
· 7 min readWhy PDF to Word Messes Up Formatting, and How to Fix It
PDF to Word layouts shift because a PDF stores fixed positions, not paragraphs, so the converter has to rebuild structure by guessing. Check whether your PDF has real text or is a scan, choose PDF to Word, PDF to Text or OCR accordingly, and then clean the .docx in Word with formatting marks, styles and section breaks.
· 9 min readHow to Reduce a PDF's Size So It Fits an Email Attachment Limit
Gmail and Yahoo cap a message at 25 MB, and Microsoft quotes 20 MB or 25 MB for Outlook, with business Exchange mailboxes often set to 10 MB. Attachments grow by about a third when encoded for email, so aim well below the headline figure: compress scans at the Recommended level first, then split by size or share a link if the file is still too large.
· 8 min readHow to Scan Documents for Online Applications With File Size Limits
Read the portal's rules first, then capture each page cropped and evenly lit at about 150 dpi (200 dpi for small print, 300 dpi for small cards like ID). Use grayscale unless colour is required, combine pages into an A4 PDF, compress it to your per-page budget, and zoom in to check every number before uploading.
· 8 min readHow to Sign a PDF Without Printing It
You can sign most everyday PDFs on screen by placing a drawn, typed or photographed signature with Fill & Sign, then checking and sending the -signed.pdf. That creates a signature image, not a certificate-based digital signature, so documents such as wills, court papers or filings that demand a qualified or certificate signature still need a proper signing service or ink.
· 8 min read