PDF Editor

The WikiPlus PDF Editor adds a visual overlay on top of the original PDF rendering — it does not modify the internal text stream objects stored in the PDF structure. To replace visible text, you cover the existing content using the eraser tool, which paints a white rectangle over the area, and then place a new text annotation on top with your corrected text. This approach works accurately for correcting a typo in a date field, updating a price on an invoice, changing a name on a certificate, or replacing a section heading. The overlay-based method is the practical standard for browser-based PDF editing because directly modifying PDF content streams requires knowledge of the document's internal font encoding and glyph mapping — information that varies by authoring tool and is not standardised across PDFs. For deep structural editing of the internal text objects, a desktop application such as Adobe Acrobat Pro is the appropriate tool. However, for everyday corrections, annotation, and form-filling, the overlay method produces fast, accurate results without installing software, creating an account, or uploading files to any external server.

No. The entire editing process runs locally inside your web browser without any server communication. Your PDF file is opened using the browser's FileReader API, passed to a WebAssembly build of the MuPDF rendering engine, and each page is drawn onto a local HTML5 canvas element. The annotation layer, where all your edits and markup live, is a separate transparent canvas overlaid on top of the rendered page images. When you click Export PDF, the annotation overlay is composited onto the original page content using pdf-lib, which also runs as a client-side library compiled to WebAssembly. The final merged file is handed back to your browser as a download. All processing happens in your browser — nothing leaves your device at any stage: no file bytes, no rendered page images, no annotation data, and no metadata. This architecture makes the tool safe for confidential contracts, personal medical records, financial statements, proprietary technical documents, and legal filings that you would not want handled by a third-party cloud service. You can verify the local processing by watching the Network tab in your browser's developer tools while editing — you will see no outbound requests carrying file data.

The WikiPlus PDF Editor toolbar provides eight distinct annotation tools. The text tool lets you click anywhere on a page and type directly; font size is adjustable from 6 to 48 points and text color is selectable from a palette or hex input. The freehand draw tool acts as a pen for signatures, handwritten notes, and freeform markup. The eraser tool paints a white rectangle over any area to conceal existing content, which you can then overlay with corrected text. The rectangle tool draws outlined or filled rectangles for highlighting regions, framing figures, or creating redaction blocks. The ellipse tool draws circles and ovals for the same purposes. The line tool creates straight lines with optional arrowheads, useful for pointing to specific parts of a document or drawing dividers between sections. The image tool inserts a PNG, JPG, WebP, or SVG image at any position and scale — common uses include company logos, stamps, or scanned handwritten notes. Every annotation supports unlimited undo and redo. You can delete individual annotations by selecting them and pressing the delete key. A clear-page button removes all annotations on the current page at once. Zoom controls let you work at up to 300 percent magnification for precise placement on complex forms.

Yes. The editor loads all pages of your PDF into the viewer and provides navigation controls at the bottom of the screen: previous page, next page, and a direct page-number input for jumping to any specific page in a long document. Annotations are stored per-page in an internal map, so edits you make on page 5 are completely independent of and do not affect pages 1, 2, 3, or any other page. You can zoom in on each page independently to work at whatever magnification gives you the precision you need for a particular page's content. When you click Export PDF, the engine iterates through every page in sequence. Pages with no annotations pass through unchanged and are copied from the original at full quality. Pages with annotations have the overlay layer composited directly onto the page content at the original page dimensions. The exported file preserves the exact page size, DPI, orientation, and colour profile of every page. This approach scales reliably to documents of any reasonable length — detailed technical manuals, multi-chapter reports, lengthy legal contracts, and multi-hundred-page reference documents all work correctly. Processing time scales linearly with page count and is typically a few seconds per annotated page on a modern device.