BigPDF — PDF 编辑、合并、拆分、签名与转换 作者： Nguyễn Văn Trình

BigPDF is a full PDF toolkit that lives in your browser — 14 of its 15 tools process your files entirely offline, with nothing ever uploaded to a server. Open a file, use a tool, download the result. That's it.

WHAT'S INSIDE

✅ Edit PDF — rotate, delete, and reorder pages; insert text and images
✅ Annotate PDF — highlight, underline, freehand drawing, notes, stamps
✅ Redact PDF — permanently black out sensitive content
✅ Watermark — stamp text watermarks across every page
✅ Page numbers — add page numbers with custom position and format
✅ Compress PDF — shrink file size (keep text, or rasterize + JPEG)
✅ Merge PDF — combine multiple files in your chosen order
✅ Split PDF — split every N pages or by custom ranges, zipped for you
✅ Extract pages — pull out just the pages you need
✅ Sign PDF — draw or type a signature, drag-and-drop it onto the page
✅ PDF → JPG — render every page as an image (zipped if multiple)
✅ PDF → Word (.docx) — extract text, line by line
✅ PDF → Excel (.xlsx) — reconstruct tables from text coordinates
✅ PDF → PowerPoint (.pptx) — one slide per page, as an image
✅ AI Assistant (optional, not offline) — summarize or ask questions about a PDF via an AI endpoint you configure with your own API key

AN HONEST LIMITATION

The Word/Excel/PowerPoint conversions run fully offline, so they preserve content, not pixel-perfect layout — Word output is line-based text, Excel reconstructs tables from text position (works best on already-tabular PDFs), and PowerPoint places one page-image per slide. True layout-perfect conversion needs a heavy server-side OCR/layout engine, which isn't something we can (or want to) run silently in your browser.

PRIVACY FIRST

• 14 of 15 tools never send your file anywhere — everything happens locally in your browser (some tools use a local WebAssembly module for speed)
• The one exception, AI Assistant, is clearly labeled, opt-in, and requires your own API key before anything leaves your browser
• No analytics and no session recording — BigPDF collects nothing
• No content scripts and no access to the pages you browse
• No account required for the free tier
• Full privacy policy: https://getpekka.com/en/privacy/bigpdf/

SIMPLE PRICING

• 5 free tool uses per week (all tools share one pool, resets weekly)
• Monthly — $9 / month, cancel anytime
• Yearly — $49 / year (save 55% vs monthly) ⭐ most popular
• Lifetime — $99 one-time, no renewal

Paid plans remove the weekly limit across all 15 tools.

PERFECT FOR

• Anyone who needs to edit, sign, or convert a PDF without uploading it to a random website
• Students and professionals merging, splitting, or extracting pages regularly
• Anyone who wants a quick redaction or watermark tool without installing desktop software
• Multilingual users — the interface is available in more than 50 languages