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Add text, images, signatures, drawings, and redactions to any PDF in three easy steps — no software to install.
Drag and drop any PDF file into the editor or click the upload button to browse your device. The document loads instantly in your browser and each page is rendered as a high-resolution canvas. Your file is never sent to a server — it stays entirely on your device from the moment you open it to the moment you download the edited version.
Use the toolbar to add text annotations, insert images, draw signatures, highlight important passages, redact sensitive content, add shapes, stamps, or sticky notes. Navigate between pages using the sidebar thumbnails. Each element can be moved, resized, rotated, and styled with custom colors, fonts, and opacity. The editor gives you full control over every detail of your document.
When you are finished, click the download button and your edited PDF is generated instantly. All your annotations, images, signatures, and redactions are permanently embedded into the document. The output file is a standard PDF that works in any PDF viewer. No watermarks are added, and the quality of the original document is fully preserved.
A powerful, private, and completely free PDF editor that runs entirely in your browser.
Every feature of the PDF editor is completely free. There are no premium plans, no per-document charges, no trial periods, and no feature gates. Add as many annotations, images, and signatures as you need to as many pages as you want — all at no cost.
Your PDF never leaves your device. All editing, rendering, and PDF generation happens entirely in your browser using JavaScript. No server uploads, no cloud storage, no third-party access. Your confidential contracts, financial documents, and personal files stay private.
Text annotations, image insertion, freehand drawing, electronic signatures, highlighting, blackout redactions, shapes, stamps, and sticky notes — all in one editor. You get professional-grade tools without installing desktop software like Adobe Acrobat.
Your edited PDF is clean and professional. We never add watermarks, branding, or any other markings to your output. The final document looks exactly as you designed it — indistinguishable from files produced by premium desktop software.
Draw your signature directly on the canvas using your mouse, trackpad, or touchscreen. The signature tool captures your natural handwriting style. Once created, place your signature anywhere on any page, resize it, and reuse it across the document.
The editor runs in any modern browser — Chrome, Firefox, Safari, or Edge — on desktops, laptops, tablets, and phones. No app downloads, no plugins, no system requirements. Open the page and start editing, whether you are on Windows, macOS, Linux, iOS, or Android.
Everything you need to know about annotating, signing, redacting, and enhancing PDF documents with ConvertKr.
PDFs are designed to be a fixed-format document — but there are countless situations where you need to annotate, mark up, or add content to an existing PDF. Signing contracts and agreements, filling in forms that lack interactive fields, adding comments and feedback to reports, redacting sensitive information from legal documents, inserting images or stamps for approval workflows, highlighting key passages in research papers, and adding sticky notes for collaborative review are just a few examples. ConvertKr's PDF editor lets you do all of this directly in your browser without installing any software.
The text tool lets you place text annotations anywhere on any page. Click where you want the text to appear, then type your content. You can customize the font family, font size, color, and opacity. Text elements can be moved by dragging, resized by pulling the handles, and rotated to any angle. This is ideal for filling in non-interactive PDF forms, adding labels to diagrams, inserting headers or footers, and annotating documents with notes or corrections. Each text element is placed as an overlay on the existing page content, so the original document is never altered.
The signature tool opens a drawing canvas where you can sign your name using your mouse, trackpad, or finger on a touchscreen. The tool captures your natural handwriting, producing a signature that looks authentic and personal. Once you draw your signature, click Apply and it appears on the page as a resizable, movable element. You can position it precisely on signature lines, resize it to fit the available space, and reuse it across multiple pages. This is perfect for signing contracts, agreements, authorization forms, and any document that requires a personal signature without printing and scanning.
The blackout redaction tool lets you permanently cover sensitive content with opaque rectangles. Click and drag to draw a blackout region over any text, image, or area you want to hide. When you download the edited PDF, the redacted areas are permanently filled — the underlying content is not recoverable. This is essential for legal documents, medical records, financial statements, and any file containing personally identifiable information (PII) that needs to be shared with third parties. Unlike some redaction tools that merely overlay a visual layer, ConvertKr's redactions are baked into the final PDF output.
The highlight tool lets you mark important passages with a semi-transparent color overlay — just like a physical highlighter pen. Choose your highlight color and drag across the text or area you want to emphasize. The freehand drawing tool gives you a pen that you can use to draw anything directly on the page: circles around important sections, arrows pointing to specific items, underlines, checkmarks, or freeform annotations. Both tools support color selection and adjustable stroke width, giving you full creative control over your markup.
The image tool lets you insert any PNG, JPG, or WEBP image onto a PDF page. Upload a company logo, a photo, a scanned document, or any graphic and position it anywhere on the page. Resize it by dragging the corner handles and move it to the exact location you need. The stamp tool provides pre-built labels like "Approved", "Confidential", "Draft", and "Urgent" that you can drop onto any page with a single click. These features are invaluable for approval workflows, branding documents, and adding visual elements to forms and reports.
ConvertKr's PDF editor uses two powerful JavaScript libraries: PDF.js (developed by Mozilla) to render each page of your PDF as a high-resolution canvas, and pdf-lib to generate the final edited PDF with all your annotations embedded. When you add elements like text, images, or signatures, they are positioned as overlays on the rendered page. When you click download, the editor recreates the PDF document, copying every original page and permanently embedding your annotations at the exact coordinates where you placed them. The entire process — rendering, editing, and PDF generation — runs locally in your browser. Your file never touches a server.
For the best editing experience, use a device with a larger screen when working with detailed annotations — though the editor works perfectly on mobile for quick signatures and stamps. If you need to edit multiple pages, use the page thumbnails in the left sidebar to navigate quickly between pages. Remember to save your work by downloading the PDF before closing the tab, as all edits exist only in your browser session. For documents that need both editing and reorganization, combine the PDF editor with the Split PDF and Merge PDF tools to extract, rearrange, and recombine pages.
Common questions about editing PDF files with ConvertKr.
Yes, completely. Every feature — text, images, signatures, drawing, highlighting, redaction, stamps, sticky notes, and shapes — is available at no cost. There are no premium tiers, no per-document charges, and no watermarks on your output. We believe essential document tools should be accessible to everyone.
Absolutely. Your PDF is processed entirely in your browser using JavaScript. It is never uploaded to any server. ConvertKr cannot see, access, or store your documents at any point. When you close the browser tab, all data is cleared from memory. This makes the editor safe for contracts, financial records, medical documents, and any sensitive file.
Yes. The signature tool lets you draw your signature using your mouse, trackpad, or touchscreen. Once drawn, your signature appears as a movable, resizable element that you can place precisely on any page. It looks natural and authentic — just like signing on paper. You can use it to sign contracts, agreements, forms, and any document that needs a personal signature.
Yes. The blackout tool lets you draw opaque rectangles over any content you need to hide. When you download the edited PDF, the redacted areas are permanently covered — the original content beneath them is not recoverable. This is suitable for removing names, account numbers, addresses, and other sensitive data before sharing documents.
No. The original pages of your PDF are preserved at their full resolution and quality. Your annotations (text, images, signatures, drawings, etc.) are added as separate layers on top of the existing content. The output PDF maintains the same visual quality as the original, with your edits permanently embedded.
The editor supports: text annotations (with custom font, size, color), images (PNG, JPG, WEBP), freehand drawings, electronic signatures, highlights, blackout redactions, shapes, pre-built stamps (Approved, Confidential, Draft, Urgent, etc.), and sticky notes. Each element can be moved, resized, rotated, and styled independently.
Yes. The editor is responsive and works on smartphones, tablets, laptops, and desktops. Any device with a modern browser — Chrome, Safari, Firefox, or Edge — can use the full editor. Touch gestures are supported for drawing signatures and positioning elements on mobile screens.
There is no imposed file size limit. Since all processing runs locally in your browser, the practical maximum depends on your device's RAM and processing power. Most modern devices handle PDFs up to 50–100 MB without any issues. For very large documents, ensure you have sufficient free memory by closing other browser tabs.