Redact PDF

Redact PDF Free Online — Blackout Text & Images loads a local .pdf into your browser and provides three primary tools: 'Blackout Text' (draw a rectangle over selectable text), 'Blackout Image' (cover raster elements), and 'Blackout Page' (mask an entire page). Workflow: click 'Open PDF' or drag-and-drop a .pdf, use the thumbnail strip to jump pages, choose a tool, draw rectangles, then click 'Apply Redactions' and finally 'Download PDF' to get a flattened .pdf. The interface also exposes 'Undo' and 'Redo' and a 'Clear All' if you want to remove markers before applying redactions.

The tool is designed for .pdf inputs and accepts single- and multi-page PDFs (file extension .pdf). It also offers an optional 'Create PDF' path where you can import images (JPG, PNG, GIF, BMP, TIFF, WebP, HEIC) which the tool converts to a PDF before redaction; individual images should be under ~50 MB to avoid mobile memory limits. For direct PDF redaction, practical limits are about 100 MB or roughly 300 pages in Chrome/Firefox on a typical 8GB laptop — larger files risk JavaScript heap errors or slow performance.

When you press 'Apply Redactions' the tool offers two modes: 'Vector Mode' and 'Raster Mode'. Vector Mode removes PDF text objects and image objects under the blackout rectangle so remaining text stays selectable; Raster Mode renders the page as a bitmap and then applies black boxes, which guarantees no recoverable text but increases file size and removes searchability. In both modes the output is flattened and the original text/objects under redactions are not preserved in the exported .pdf, so redaction is effectively irreversible — keep the original file if you may need to revert.

You do not need an account or sign up to use Redact PDF Free Online — Blackout Text & Images; there is no forced upload to a remote server for processing. The default behavior is in-browser processing: when you click 'Open PDF' the file is read into memory by the browser's JavaScript engine and redactions are applied locally. That said, heavy files may trigger optional cloud-assisted rendering in rare cases (you are prompted and must opt in); if you want strict local-only, avoid any cloud prompts and work in Chrome or Firefox which handle local processing best.

Blank pages or 'Canvas failed to load' usually mean the PDF uses encryption, uncommon fonts, or very large images that exhaust browser memory; check if the file is password-protected or an Adobe XDP form. If you see that error, try opening a linearized/optimized version (save as 'Optimized PDF' from Acrobat) or split the file into smaller chunks via 'Create PDF' > 'Split' before redacting. Also switch to Chrome or Firefox on desktop — Mobile Safari is more likely to hit a memory ceiling for files >50 MB. If blackouts render but don't persist after download, ensure you pressed 'Apply Redactions' and then 'Download PDF' rather than just leaving the canvas.

Use the thumbnail pane on the left: select the first page, draw your blackout, then choose 'Propagate to pages' and enter a page range (for example 1-10 or 1,3,5). The tool will duplicate the same rectangle coordinates across the selected pages. For whole-document removal use 'Blackout Page' and then 'Apply to All Pages' which inserts a full-page mask; remember that 'Apply to All' in Vector Mode preserves vector content elsewhere but in Raster Mode it will rasterize every page and likely increase file size significantly.

Redaction affects PDF size depending on mode: Vector Mode generally keeps file size similar or slightly smaller since it removes objects, while Raster Mode converts pages to bitmaps and can multiply file size. The export dialog includes a 'Compression' slider and preset DPI choices (150, 300) — 150 DPI is suitable for on-screen viewing and keeps files small, 300 DPI preserves print quality but can double or triple file size. If size matters, choose Vector Mode plus 'Strip Metadata' and 150 DPI compression; if you need absolute removal of embedded text, choose Raster Mode but expect larger files.

Scanned PDFs are image-based and generally require Raster Mode to guarantee removal: the 'Blackout Image' tool covers the embedded image layer directly. This tool does not include built-in OCR — it won’t convert scanned pages into selectable text before redaction. If you need searchable output, run OCR in Acrobat, Tesseract, or an OCR service first, then open the OCR'd PDF here and use Vector Mode where possible; otherwise redact in Raster Mode and re-run OCR after export if you need searchable text.

Desktop Chrome and Firefox offer the most stable experience for files above ~50 MB; they provide more memory and better JavaScript engines. On iOS Safari you may hit memory limits earlier and HEIC images can convert poorly when using the 'Create PDF' path, producing blank or rotated pages — on iPhone convert HEIC to JPG first or use Chrome on iOS if available. Android Chrome works well but watch for file-picker limits and avoid very large PDFs (>80–100 MB) on phones; for best results perform large redactions on a desktop.

When you click 'Apply Redactions' you can enable an option labeled 'Strip Metadata & Annotations'. With that option on, visible annotations (comments, sticky notes), form fields are flattened into the page, and common metadata (XMP, title, author) is removed. Invisible layers (optional content groups) and some embedded file attachments are removed in Vector Mode if they are under a blackout, but complex embedded objects or hidden JavaScript may require an extra 'Flatten Forms' step or rerun through a PDF sanitizer like Adobe's Preflight; the tool aims to remove most common traces but does not claim the full sanitization compliance of specialized enterprise redaction suites.

Once you click 'Apply Redactions' and then 'Download PDF', the exported file is flattened and redaction is irreversible in that copy; there is no server-side versioning to recover changes. The in-app editor does have an 'Undo' stack and a 'Revert to Original' button that works before you apply redactions, so you can revert while still editing. Best practice: always keep a backup of the original .pdf (use 'Download Original' or save a copy before starting) so you can reopen it if you need to recover mistakenly redacted content.

Acrobat Pro includes advanced features like pattern-based search-and-redact, redaction logs, batch search rules, and certified sanitization for legal standards; Photoshop rasterizes pages and gives pixel-level control but destroys text searchability. Redact PDF Free Online — Blackout Text & Images is a free, in-browser alternative that removes content locally without signup and offers vector and raster redaction modes, but it lacks enterprise features like redaction auditing, automated PII detection, and deep metadata sanitization. For legal or compliance-sensitive work use Acrobat Pro for audit trails; for quick, offline-safe redactions without an account this tool is a practical, no-cost option.