Security6 min read
How to redact a PDF properly (and why black boxes are not enough)
Drawing a black rectangle over text hides it on screen but leaves it in the file. Here is what real redaction removes and how to check your output.
The PDF100 blog
Clear explanations of what each tool does, when it works well, and how to keep your documents private.
Start here: five essential tools
Guides5 min read
How to compress a PDF without ruining it
Why some PDFs shrink by 90% and others barely change, and how to pick the right compression level for email, web or print.
Privacy5 min read
Are online PDF tools safe? How to check before you upload
Most PDF websites upload your file to a server. Here is how to tell which kind of tool you are using, and a 30-second test you can run on any site.
Guides4 min read
How to merge PDF files and keep bookmarks and forms intact
A simple merge is easy. Keeping bookmarks, fillable fields and page order right takes a little more care. Here is what to watch for.
Guides5 min read
PDF to Word: what converts well and what does not
Why converted documents sometimes look different from the original, which PDFs convert cleanly, and what to do with scans.
Security4 min read
How to password protect a PDF: open passwords vs permissions
The difference between a password that locks the file and one that only restricts printing or copying, and which one actually protects your data.
Guides5 min read
How to split a PDF: by page range, file size or bookmark
Four ways to break a large PDF into smaller files, and which one to pick for email limits, chapters or pulling out a single page.
Guides6 min read
How to make a scanned PDF searchable with OCR
A scan is a picture of text. OCR recognizes the words so you can search, select and copy them. Here is how to get clean results.
Guides5 min read
How to sign a PDF without printing it
Draw or type a signature and place it on any page. Plus the difference between a visible signature and a certified digital signature.
Guides4 min read
How to fill in a PDF form online
Fillable forms, flat forms that only look fillable, and how to make sure the answers you typed are still there when someone else opens the file.
Guides4 min read
PDF to JPG, PNG or WebP: which image format should you choose?
Converting PDF pages to images is easy. Choosing the right format and resolution is what decides whether the result looks sharp or muddy.
Guides4 min read
How to turn photos into a single PDF
Combine phone photos, screenshots or scans into one tidy PDF, in the right order and at a sensible file size.
Privacy5 min read
The hidden data inside your PDFs, and how to remove it
Author names, editing software, comments, attachments and scripts can all travel with a PDF. Here is what to strip before sharing a file publicly.
Guides5 min read
Page numbers, headers and Bates numbering explained
When a simple "Page 3 of 10" is enough, and when legal or audit work calls for Bates numbers that run across a whole set of documents.
Guides4 min read
How to watermark a PDF (and what a watermark can and cannot do)
Add "Draft", "Confidential" or your logo to every page. Plus why a watermark deters casual copying but is not a security control.
Guides4 min read
How to rotate, reorder and delete pages in a PDF
Fix sideways scans, put pages in the right order and drop the blank ones, without retyping or rescanning anything.
Guides4 min read
How to compare two versions of a PDF
Find what changed between two drafts of a contract or report, without reading both side by side line by line.
Guides5 min read
How to fix a PDF that will not open
Damaged downloads, truncated email attachments and broken exports. What Repair PDF can recover, and what to try when it cannot.
Guides5 min read
How to get tables out of a PDF and into Excel
Why PDF tables are tricky to extract, how PDF to Excel and PDF to CSV handle them, and how to clean up the result.
Guides4 min read
How to print a PDF as a booklet
Turn a normal PDF into folded, stapled booklet pages, and fit several pages onto one sheet for handouts.