What KTPDF can do
The same engine runs in the app and in the browser. Where they differ, it says so.
Change the content
Edit existing text
Click a line of text in the file and retype it. The new text is real text — still selectable, still searchable, not a picture pasted on top.
Add a text box
Put text anywhere, pick the font, size and colour. The font is sampled from the nearest text, so it does not clash with the rest of the page.
Insert images and signatures
Drag an image in, resize it, crop it, drop the white background or turn it black and white — enough for a signature photographed with a phone.
True redaction
Draw a box and the text leaves the file, rather than hiding under a black rectangle. Text blacked out the old way can still be copied out — the mistake that has leaked court filings more than once.
Rearrange the document
Merge files
Join several PDFs into one. Drag to reorder before saving.
Split files
Pull out a page range, or cut the file into several parts.
Reorder pages
Drag to reorder, rotate, delete, insert a blank page or a page from another file.
Images to PDF
Drop a set of images into the window and get a PDF, one image per page.
Annotate and mark up
Highlight, underline, strike through
Select text and it becomes a mark. The stripe follows the size of the text instead of being a block of colour dropped on top.
Freehand, boxes, arrows
Annotate by drawing. Stored as vectors, so it stays sharp in print and when zoomed.
Watermarks
Stamp faint text or an image across every page — "DRAFT", a company name, your own mark.
Read and print
Vietnamese-aware search
Typing without diacritics still finds accented text. Results come with the surrounding sentence so you know it is the right spot.
Outline and page thumbnails
Jump around a long file; the sidebar shows every page.
Open password-protected files
Locked files open once you supply the password.
Prints exactly what is on screen, including edits you have not saved yet.
Where your file lives
Nothing is uploaded anywhere
Everything runs on your own machine — the app and the browser build alike. There is no step where the file is sent away and comes back.
Save over the original
The app does it directly. In the browser, Chrome and Edge allow it; elsewhere you get a new file downloaded.
Which one to use
Same engine inside. Use whichever is handier.
Desktop app
For everyday use, or when the file is big.
- Handles files of several hundred pages
- Saves over the original file
- Double-click a PDF to open it
- Remembers recent files and where you stopped
- No internet needed
In the browser
For a quick job, or on a computer that is not yours.
- Nothing to install
- Does everything the app does
- Your file still stays on the machine
- Saves over the original in Chrome and Edge
- Safari and Firefox download the new file