What is a PDF annotation, and why does whiting-out text not remove it?
An annotation is an object attached to a page on top of its content: highlights, underlines, strike-throughs, sticky notes, free text, ink drawings, shapes, stamps and signature fields are all annotation types defined in ISO 32000, stored in the page's /Annots array and editable or removable later. Flattening draws them permanently into the page content. The PDF editor on this site keeps only highlights, underlines, strike-throughs (unless you choose to flatten them) and sticky notes as annotations; the text, drawings, shapes, stamps and signature images it adds are written straight into the page content and are permanent. A white rectangle drawn over text is exactly that — a shape on top — so the text beneath still exists, copies and searches; only redaction, which deletes the underlying content, removes it.
Security note: Covering text with a shape is not redaction: the hidden text remains in the file and can be selected, extracted or found by search. Use a redaction tool that removes content, then check the result by searching for the removed text.
Read the guide: How to Edit a PDF Without Uploading It
How to use Add Text to PDF
- Drop a PDF.
- Click where the text should start and type.
- Adjust size, colour or alignment in the toolbar.
- Click "Save PDF" and download.
Add Text to PDF features
- Click to place, type, drag to move
- Font size 8–64, colour, bold, alignment, opacity
- Multi-line text with Enter
- Arabic shaped right-to-left, Devanagari conjuncts, embedded fonts
- Real searchable text in the output
- Whiteout on the same toolbar to replace a line
Add Text to PDF example
Fill in a form that has no fields
Input:
Click each blank, type the value; size 11, blackOutput:
application-text.pdf — the values are selectable text in the fileFrequently asked questions about Add Text to PDF
Is the text searchable in the saved PDF?
Yes. It is written as text with an embedded font, not as an image, so readers can select, search and copy it.
How do I replace text that is already on the page?
Use the whiteout tool to cover the old text with a white box, then add the new text on top. To remove the old text from the file rather than cover it, use Redact PDF.
Which fonts can I use?
The editor uses Cairo (Latin and Arabic) and Noto Sans Devanagari (Hindi), regular and bold, in any size. Both are embedded as subsets, so the file grows by a few kilobytes.
Is my PDF uploaded to a server?
No. The file is opened and processed by your browser with WebAssembly and JavaScript; nothing is sent to Mutqan Soft or anyone else. Close the tab and the file is gone. Downloading the result needs a free account — no subscription, no payment.
Can I use it on a password-protected PDF?
Yes, if you know the password: the file list asks for it once and every operation then works on the decrypted pages. The output is saved without a password unless you protect it again.
Technical notes
Each text box is stored with its bounding box and an upright rotation for the page orientation it was created on, then drawn line by line with the shared text engine (bidi-js runs, Cairo / Noto Sans Devanagari subsets through @cantoo/fontkit). The on-screen editor is a textarea in the same face and size laid over the page.
References
- ISO 32000-2:2020 — Document management — Portable document format — Part 2: PDF 2.0The current PDF standard: file structure, objects, pages, fonts, annotations, forms and encryption.
- PDF Reference — ISO 32000-1:2008 (PDF 1.7), Adobe copyThe freely readable PDF 1.7 specification: page trees, content streams, metadata, permissions and the standard security handler.
- PDF.jsThe open-source PDF renderer that draws PDF pages in the browser without a plugin — how documents are previewed locally.