What does redact a PDF mean?

Redacting a PDF means permanently removing or blacking out sensitive content — names, addresses, account numbers, social security numbers, signatures, or anything else that shouldn't be in the published version. Proper redaction has two parts: a visual black rectangle covering the content, AND a content-stream scrub that actually deletes the underlying text from the PDF. Without the second part, anyone can recover the redacted text by selecting it, copying, or running text extraction — the famous redaction-fail problem that's burned governments, law firms, and Fortune 500 companies repeatedly.

How do I redact a PDF?

Drop the PDF on pdfedit.com/redact-pdf. The editor opens with the redaction tool active. Drag a black rectangle over any text, image, or region you want gone. The redacted content is permanently removed — visual cover + content-stream scrub. Save the redacted PDF. No account, no upload, no Adobe Pro.

How do I redact a PDF for free?

Use this tool — 100% free, no signup, no daily quota, no Adobe Pro $19.99/month subscription. Drop the PDF, drag rectangles over the content to redact, save. The redaction runs entirely in your browser using pdf-lib.

How do I redact a PDF without Adobe Pro?

Use pdfedit.com/redact-pdf. Adobe Acrobat Pro charges $19.99/month for redaction; ours is free, runs in your browser, and provides the same content-stream scrub Adobe does (visual cover + underlying text deletion). The difference: Adobe also runs server-side in their web version (your PDF uploads to Adobe's servers); we run 100% locally.

How do I redact text in a PDF?

Drop the PDF here. After the one-time permanence warning, drag a rectangle over the specific text you want to remove. The text is deleted from the PDF's content stream — it's not searchable, not selectable, not extractable, not recoverable from the saved file.

How do I redact information on a PDF?

Same answer — drop the PDF, drag rectangles over the information you want gone (names, account numbers, signatures, photos, anything). The redaction deletes both the visual content and the underlying text data.

How do you redact in PDF?

Three steps: (1) drop the PDF on this page; (2) confirm the permanence warning; (3) drag rectangles over what you want gone. Save when done.

Is this PDF redaction tool free?

Yes. 100% free forever — no trial, no premium tier, no per-file charge, no daily quota. Adobe Acrobat Pro charges $19.99/month for the same feature.

No. The redaction runs entirely in your browser. This matters MORE for redaction than for any other PDF operation — the content you're redacting is by definition the most sensitive thing in the document (legal privilege, PII, trade secrets, healthcare data). Uploading a PDF to redact it on someone else's server is structurally backwards. Smallpdf, iLovePDF, PDF24, and Adobe's web version all upload. We don't.

Is the redaction permanent?

Yes. The redacted content is permanently removed from the PDF's content stream — not just covered with a black rectangle. Search engines, OCR tools, copy-paste, and text-extraction tools all return nothing for the redacted region. This is what Adobe calls 'true redaction' and what court rules require for legal filings.

What's the difference between redaction and a black rectangle on top?

Critical difference. A black rectangle on top of text (using a markup tool, image, or basic 'cover' tool) only hides the text visually. The underlying text is still in the PDF — anyone can select it, copy it, run text extraction, or use OCR on a screenshot to recover it. Real redaction (what we do, what Adobe does) deletes the underlying text from the content stream. Visually identical, but the data is actually gone. The Manafort court filing scandal in 2019 was a famous redaction-fail where a US prosecutor submitted a 'redacted' filing where the text was just covered, and journalists copy-pasted to reveal the contents within minutes.

Can I redact images and signatures, not just text?

Yes. The black rectangle covers anything in its bounds — text, images, signatures, scanned content, lines, shapes. The visual cover is opaque black, and any text under the rectangle is also content-stream deleted.

Can I undo a redaction?

Inside the editor session, yes — Ctrl+Z works on redact rectangles like any other element. After you Save and download, the redaction is permanent in the saved file. There's no recovery from a saved redacted PDF (which is the whole point — if redactions could be undone, they'd be useless).

Why is the confirmation modal there before I can redact?

Same reason Adobe shows one — redaction is permanent in the saved file. The one-time modal makes sure you're not redacting accidentally. After confirming once per session, you can drag as many redaction rectangles as you want without further prompts.

Is redacting a PDF legal?

Yes — redaction is the standard practice for filing legal documents publicly while protecting privileged or private information. US courts, the GDPR (EU), and HIPAA (US healthcare) all explicitly require redaction for certain content categories. The legal question isn't whether redaction is legal, it's whether the redaction was done properly — which is why content-stream scrub matters more than just a black rectangle.

Is there a file-size limit?

No artificial limit. Memory is the only ceiling.

Does it work on mobile?

Yes — iPhone Safari, iPad, Android Chrome — though redaction is much more accurate with a mouse than a finger. For high-stakes redaction (legal filings, medical records) use a desktop.

Does it work offline?

Yes once the page has loaded. The PDF Edit engine is cached in your browser.

What is the best free PDF redaction tool?

For privacy-first redaction with no upload, no Adobe Pro paywall, and true content-stream scrub (not just a visual black rectangle), we believe pdfedit.com is the best free option. For desktop-only batch automation, Adobe Acrobat Pro is the gold standard but costs $19.99/month and requires the desktop app. Most other free 'redaction' tools online either upload your file or only draw a black rectangle without scrubbing the underlying text — neither is acceptable for genuinely sensitive content.

塗黑 PDF — 免費、喺你個瀏覽器、唔使 Adobe Pro

永久塗黑敏感文字、姓名、帳戶號碼、簽名同圖片。真正嘅內容流塗黑 — 唔係淨係頂面一個黑色方框。

Drop a PDF — the editor opens with the redaction tool active. Drag a rectangle over anything you want gone (text, images, signatures), and the redacted content is permanently removed from the file. Visual black box 加上 underlying content-stream scrub: search engines, OCR tools, and text-extraction utilities all return nothing where the redaction sits. The same engine the PDF Edit editor ships, running 100% in your browser. No upload, no signup, no Adobe Pro $19.99/month paywall.

100% 永久免費無需帳戶 100% 在您的裝置上 Military-Grade Encryption

文件永遠不會離開您的設備

AES-256 加密

我們看不到您的文件

無需連接

點解本地處理對塗黑比任何其他操作都更重要

塗黑係 PDF 操作裡面唯一一個你處理嘅內容根據定義就係文件入面最敏感嘅內容 — 法律特權、個人識別資訊、商業機密、醫療紀錄。但係其他每一個免費網上塗黑工具 — Smallpdf、iLovePDF、PDF24、Adobe 嘅網頁版 — 喺俾你做塗黑之前都要你上傳嗰啲內容到佢哋嘅伺服器。

That's structurally insane. 塗黑嘅重點就係敏感內容唔應該離開你嘅控制。 We run the redaction in your browser tab. There is no server-side copy of your PDF — pre-redaction or post-redaction.

將你嘅 PDF 拖到呢度

或者

唔使上傳。PDF 載入完之後塗黑工具會自動啟動。

點樣塗黑 PDF — 一步一步

拖你嘅 PDF

Drag any PDF onto the dropzone above, or click 揀 PDF to browse. The file loads into your browser memory only — no server upload at any point.
確認永久性警告

一次性彈窗會警告你塗黑係永久嘅 — 同 Adobe Acrobat Pro 顯示嘅警告一樣。撳繼續入塗黑模式。（每節只見一次。）
喺敏感內容上拖方框

喺你想清除嘅任何文字、姓名、號碼、簽名或圖片上拖一個黑色方框。每個方框都會由 PDF 嘅內容流刪除底層內容 — 唔係淨係視覺上遮住。
儲存塗黑後嘅 PDF

Click Save to download. The redacted content is permanently gone from the saved file — anyone who opens it in Acrobat, Preview, or any text-extraction tool gets nothing back where the redaction sits. 呢個係永久嘅: keep an unredacted copy of the original if you might need it later.

真正塗黑 vs 畫一個黑色方框

The single most important thing about PDF redaction: 視覺上遮住文字唔係塗黑. If you use a markup tool, image overlay, or basic "cover" feature to put a black rectangle on top of text, the underlying text is still in the PDF file. Anyone can:

點擊同拖選「塗黑咗」嘅文字 — 文字仲喺度
複製同貼上嗰個選擇 — 完整內容恢復
用任何文字編輯器打開 PDF → 文字會以純 XML / 內容流出現
對頁面截圖做 OCR 嚟恢復可見部分

This is the famous 塗黑失敗 problem that has burned governments, law firms, and Fortune 500 companies. The 2019 Manafort court filing where US prosecutors "redacted" a document and journalists copy-pasted to reveal the contents within minutes is the textbook case.

Real redaction (what we do, what Adobe Acrobat Pro does, what court rules require) has two layers: 視覺黑色方塊覆蓋內容, AND 內容流清除 that actually deletes the text from the PDF's underlying data. Visually identical, but the text data is genuinely gone.

塗黑 PDF 對 Adobe Acrobat Pro、Smallpdf、iLovePDF、PDF24

功能	PDF Edit	Adobe Acrobat Pro	Smallpdf	iLovePDF	PDF24
PDF 上傳到伺服器？	冇 — 100% 本地	係（網頁）/ 冇（桌面）	係	係	係
費用	永遠免費	$19.99/month	免費 + 收費	免費 + 收費	免費 + 收費
需要帳戶？	永遠唔使	係	免費版有限制	免費版有限制	免費版有限制
真正內容流塗黑（文字真係刪除）？	係	係	視等級而定	視等級而定	因情況而異
永久性警告？	係（一次性確認）	係	有限制	有限制	冇
每日上限？	冇	冇（收費）	免費每個鐘 2 個任務	免費版有上限	按等級
輸出有水印？	冇	冇	免費版：部分	部分工具	冇
載入後可離線運作？	可以	桌面版有 / 網頁版冇	冇	冇	冇

如果你有份敏感文件想做一次性塗黑，揀擇好殘酷：俾 Adobe $20/month 用桌面版做正式塗黑，或者用某個免費網頁工具，但要將你嘅敏感內容上傳去佢哋嘅伺服器。又或者用呢個 — 免費、本地、用同 Adobe 一樣嘅內容流清除。

邊啲人會塗黑 PDF？

律師 + 律師助理

法庭存檔、證據開示、FOIA / 公開紀錄回應。大部分美國司法管轄區嘅法庭規則要求任何公開存檔且包含特權或個人識別資訊嘅文件必須做真正塗黑（內容流清除）。

人力資源 + 招聘

喺內部同審查者分享申請者履歷，但塗黑佢個名同聯絡資料以保持篩選公平。又或者喺分享聘用信前將薪酬資料塗黑。

醫療行政

為研究、第二意見或保險而分享嘅 HIPAA 涵蓋紀錄 — 分享前將病人識別資料塗黑。

合規 + 審計

同核數師、監管機構或外部律師分享嘅財務文件 — 帳戶號碼、客戶姓名同商業機密數字按範圍塗黑。

政府 + 公共紀錄

FOIA / 公開紀錄法案回應，當文件嘅部分受豁免條款保留 — 真正嘅塗黑係公開發布嘅法律標準。

任何分享敏感 PDF 嘅人

有帳戶號碼嘅銀行月結單、有地址嘅身份證、簽咗嘅合約但你只想分享關鍵條款 — 將唔應該流出去嘅嘢塗黑。

PDF 入面嘅塗黑係咩意思？

In the PDF context, "redact" means 永久咁從 PDF 頁面移除或塗黑內容, in a way that the removed content cannot be recovered from the saved file. The word comes from editorial usage — "to redact" originally meant to edit a document for publication, including censoring sensitive parts. In digital PDFs, proper redaction has a specific technical meaning: both the visible content (covered with an opaque black rectangle) AND the underlying content-stream data (the actual text bytes in the PDF file) are removed.

常見要塗黑嘅嘢：

個人識別資料 — 姓名、地址、社會安全號碼、電話號碼、電郵地址
財務細節 — 帳戶號碼、信用卡號碼、銀行路由號碼、薪金數字、交易金額
法律特權 — 律師客戶特權通訊、工作成果、和解金額
商業機密 — 專利配方、客戶名單、供應商名稱、定價資料
醫療保健 — 病人姓名、診斷、治療日期、處方（HIPAA 涵蓋）
簽名 + 相片 — 任何出現簽名、身份證相或其他視覺識別嘅地方

常見問題

點樣塗黑 PDF？

將 PDF 拖到上面個版面。編輯器會打開並啟動塗黑模式。喺要清除嘅內容上拖出方框。儲存。

點樣免費塗黑 PDF？

用呢個工具 — 100% 免費，唔使註冊，冇每日配額，唔使 Adobe Pro $20/month 訂閱。

點樣唔使 Adobe Pro 塗黑 PDF？

用 pdfedit.com/redact-pdf — 同 Adobe 一樣嘅內容流塗黑、免費、喺你個瀏覽器、唔會上傳。

塗黑 PDF 係咩意思？

永久咁從 PDF 移除或塗黑敏感內容，令到被移除嘅內容無法復原。真正嘅塗黑 = 視覺黑色方塊 + 內容流清除。淨係用方框遮住文字並唔係塗黑。

點樣塗黑 PDF 入面嘅文字？

喺文字上拖出方框。文字會由 PDF 嘅內容流刪除 — 唔搜得到、唔揀得到、唔提取得到。

點樣塗黑 PDF 上嘅資訊？

答案一樣 — 喺你想清除嘅資訊（姓名、帳戶號碼、簽名，乜都得）上拖方框。

塗黑係永久嘅嗎？

係。被塗黑嘅內容會由 PDF 嘅內容流永久移除。搜尋引擎、OCR 工具同文字提取程式對於塗黑區域全部都返回空白。

塗黑同黑色方框有咩分別？

頂面嘅黑色方框只係視覺上遮住文字 — 任何人都可以複製貼上恢復底層文字。真正嘅塗黑（我哋做嘅嘢）會由檔案內刪除底層文字。視覺一樣，但資料真係冇咗。

可以塗黑圖片同簽名嗎？

係。黑色方框會遮住範圍內嘅任何嘢 — 文字、圖片、簽名、掃描內容。

可以撤銷塗黑嗎？

係，喺編輯器會話內（Ctrl+Z），唔係保存同下載後。保存後，遮蓋係永久性嘅。

我嘅 PDF 會上傳嗎？

唔會。塗黑完全喺你個瀏覽器內進行。呢一點對塗黑嚟講比任何其他 PDF 操作都重要 — Smallpdf、iLovePDF、PDF24 同 Adobe 嘅網頁版全部都會上傳。我哋唔會。

塗黑 PDF 合法嗎？

Yes — redaction is the standard practice for sharing legal documents while protecting privileged content. US courts, GDPR, and HIPAA all require redaction for certain content. The legal question is whether the redaction was done 妥當咁 — which is why content-stream scrub matters.

有檔案大細限制嗎？

冇人為限制。

喺手機上可以用嗎？

可以，但用滑鼠做塗黑會比用手指準確好多。重要嘅塗黑請用桌面。

離線可以用嗎？

頁面載入之後就可以。

最好嘅免費 PDF 塗黑工具係邊個？

如果你想要無上傳、無 Adobe Pro 收費牆嘅私隱優先塗黑，並有真正嘅內容流清除，我哋認為 pdfedit.com 係最好。對於桌面 / 批次自動化，Adobe Acrobat Pro 係黃金標準，但要 $19.99/month。

關於呢個工具： 呢度嘅塗黑引擎同我哋主編輯器嘅塗黑工具係同一個 — 放低你嘅 PDF，編輯器就會打開，標記工具嘅塗黑子模式已經預先啟用。一個真理來源，冇重複嘅塗黑代碼。PDF 永遠唔會離開你部裝置 — 視覺黑色方塊同內容流清除全部都喺你個瀏覽器透過 pdf-lib 進行。

Last updated: 2026-05-13