Edit PDF
Place text anywhere on your PDF pages. Choose fonts, sizes, and colors to match your document. Add labels, notes, or corrections directly onto your PDF.
Drop a PDF file to add text
or click to browse from your device
Your files stay on your device — 100% private
How it works
Upload your file
Drag & drop or click to select. Files stay on your device — nothing is uploaded.
Adjust settings
Configure options and preview before processing.
Download result
Get your file instantly. No signup, no email required.
Frequently Asked Questions
Related Tools
Need more PDF tools?
Explore our full suite of 30+ free PDF tools — all running securely in your browser.
Browse All ToolsWhat Is PDF Editing?
PDF editing refers to the ability to modify the content of an existing PDF document. While PDFs were originally designed to be a fixed, read-only format, modern tools make it possible to add text annotations, labels, notes, and corrections directly onto PDF pages.
One23PDF's Edit PDF tool lets you place text anywhere on a PDF page. Choose from a variety of fonts, sizes, and colors to match the document's existing style. Whether you are filling in a form field that is not interactive, adding a note to a contract, or labeling a diagram, the editor gives you precise control over placement and formatting.
All editing happens in your browser. Your PDF is never uploaded to a server, making One23PDF a safe choice for sensitive documents like tax forms, legal agreements, and medical records. The edited PDF downloads as a new file, preserving your original document intact.
Benefits of Editing PDFs Online
No Software Required
Skip expensive desktop applications. One23PDF works in any modern browser — Chrome, Firefox, Safari, or Edge — on any operating system. There is nothing to download, install, or update.
Add Text Anywhere
Click any spot on the page and start typing. Position text with pixel-level precision, adjust font size and color, and see a live preview of your edits before saving.
Complete Privacy
Your documents never leave your device. One23PDF processes everything client-side, so confidential financial reports, legal contracts, and personal forms stay completely private.
Non-Destructive Editing
The original PDF is never altered. One23PDF generates a new file with your changes applied, so you always have the original to fall back on if needed.
How to Edit a PDF with One23PDF
- 1
Upload your PDF
Drag and drop your PDF file onto the upload area, or click to browse. The file is loaded locally in your browser — no upload to any server occurs.
- 2
Select the text tool
Click the text tool and then click anywhere on the PDF page where you want to add text. A text input will appear at that location.
- 3
Type and format
Enter your text and adjust the font, size, color, and alignment. You can reposition the text by dragging it to the exact spot you need.
- 4
Add more annotations
Repeat the process to add as many text annotations as you need across multiple pages. Preview each page to ensure everything looks correct.
- 5
Download the edited PDF
Click Download to save your edited PDF. The new file includes all your text additions while preserving the original document content.
Common Use Cases for PDF Editing
- Filling in non-interactive PDF forms — tax documents, applications, and government forms
- Adding notes or corrections to contracts before signing
- Labeling architectural drawings, floor plans, or engineering diagrams
- Annotating academic papers or student assignments with feedback
- Adding a "DRAFT" or "APPROVED" label to documents for internal review
- Inserting missing information on invoices or purchase orders
- Creating annotated screenshots or mockups for design reviews
How Browser-Based PDF Editing Works
One23PDF renders your PDF pages using a combination of pdf.js for display and pdf-lib for modification. When you add text, the editor calculates the exact coordinates on the PDF page and embeds a new text annotation at that position. Fonts are embedded in the output file to ensure the text displays correctly on any device.
The rendering engine preserves all existing content — text, images, vector graphics, and form fields — while layering your annotations on top. This non-destructive approach means the original PDF data is never altered or recompressed. The output file is a valid, standards-compliant PDF that opens in any reader.
For large PDFs with hundreds of pages, One23PDF loads pages on demand rather than processing the entire document upfront. This keeps memory usage low and ensures smooth performance even on tablets and smartphones.
Combining Editing with Other One23PDF Tools
PDF editing is often just one step in a larger workflow. After adding text, you might want to <a href="/sign-pdf">add a signature</a>, <a href="/add-page-numbers">insert page numbers</a>, or <a href="/merge-pdf">merge the edited document</a> with other files. One23PDF's entire tool suite runs in the browser, so you can chain operations together without re-uploading your file between each step.
One23PDF vs. Other PDF Editors
Adobe Acrobat Pro is the industry standard for PDF editing, but it costs $19.99 per month and requires desktop installation. Free alternatives like PDF-XChange Editor are Windows-only. Browser-based editors from Smallpdf and ILovePDF offer convenience but upload your files to cloud servers and impose daily usage limits.
One23PDF combines the convenience of a browser-based tool with the privacy of desktop software. Your files never leave your device, there are no usage limits or watermarks, and the tool works on any platform with a modern browser. For users who need to make quick text additions to PDFs without paying for a subscription, One23PDF is the ideal solution.
For more advanced editing needs — such as modifying existing text or editing images within a PDF — dedicated desktop software may still be necessary. However, for the most common editing tasks like adding annotations, labels, and form entries, One23PDF covers the vast majority of use cases.