Cover sensitive regions with black rectangles using PDF-point coordinates. Define multiple regions across pages while keeping the original layout.
Drag & drop files here, or
Updated
Redact PDF on Synthixx Tools is a free browser-based utility: upload your file, configure options, run the job, and download the result with no account and no watermark. Black-box redact regions on PDF pages.
Redact PDF runs entirely in your browser session against our secure API. There is no desktop install, no watermark on outputs, and no requirement to create an account for standard jobs. Keep reading for when to use this tool, practical tips, and honest limits.
Use Redact PDF when your goal matches the tool name and you want a free online workflow with clear privacy cleanup. Prefer related tools on this site if you need a different step in the same document pipeline.
Pick Redact PDF when the primary keyword intent matches your task. For multi-step pipelines (OCR → compress → protect), run each step with the matching tool rather than expecting a single upload to do everything. Related tools are linked at the bottom of this page.
For best results with Redact PDF: use clear filenames, stay within size limits listed in the upload UI, and preview pages when available before you run the job. Re-download promptly — outputs are temporary.
Stay within the upload limits shown in the tool UI. If a job fails, re-check file type and corruption (try Repair PDF). For password-protected inputs, unlock first. After success, download immediately and delete local copies you no longer need.
Synthixx Tools processes files for your requested job only. Transfers use HTTPS; completed job files are scheduled for automatic deletion. We do not sell your documents.
Privacy-first processing is a core product rule: uploads are used to fulfill the tool job you start, not for advertising profiles. Do not upload highly sensitive materials to any free online tool unless your threat model allows it — that advice applies industry-wide, including competitors. For account features (Design cloud sync), sign-in pages are noindexed; tool pages remain the public SEO surface.
After Redact PDF, continue with related PDF or image tools on Synthixx — merge, split, compress, convert, OCR, protect, and AI PDF Studio — all free and linked from this page.
Internal workflows that often follow Redact PDF include compress for email size, protect for sharing, OCR for searchable archives, and AI PDF Studio for summaries or Q&A. Browse the PDF Tools category hub for the full catalog. Image Resizer and Image Compressor cover bitmap workflows when your output is a picture rather than a PDF.
Black rectangles cover content visually. For irreversible sanitization of all underlying text/objects, use a dedicated sanitizer after redaction.
Provide JSON regions with page (1-based), x, y, width, and height in PDF points (origin bottom-left).
Files are processed securely and automatically deleted after your job completes.