> ## Documentation Index
> Fetch the complete documentation index at: https://docs.formepdf.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Redaction

> How Forme performs true PDF redaction — content stream text removal, metadata scrubbing, and compliance-grade sensitive data removal.

Forme performs true PDF redaction: text is removed from the content stream, not just hidden behind a black box. This is the difference between compliance-grade redaction and a cosmetic overlay that can be trivially reversed.

***

## Why Black Boxes Aren't Enough

A black rectangle drawn over text in a PDF does not remove the text — it only hides it visually. The text remains in the PDF content stream and can be extracted by:

* Copying and pasting from the PDF
* Using PDF text extraction tools
* Inspecting the raw PDF file

This is not a theoretical risk. Improperly redacted court documents, government filings, and legal briefs have leaked sensitive information because authors used annotation-based "redaction" tools that only add a visual overlay.

***

## How Forme Redacts

When you call `POST /v1/redact`, Forme:

1. **Decompresses content streams** — PDF content streams use FlateDecode compression. Forme decompresses them to access the raw page description operators.

2. **Identifies text operators** — PDF draws text using operators like `Tj` (show text), `TJ` (show text with positioning), `'` (move to next line and show text), and `"` (set spacing and show text). Forme identifies which text operators fall within redaction regions.

3. **Removes text operators** — Text operators within redacted regions are removed from the content stream entirely. The text data no longer exists in the PDF.

4. **Draws visual overlay** — A black (or custom-colored) rectangle is drawn where the text was, providing a clear visual indicator that content has been redacted.

5. **Recompresses content streams** — The modified content stream is recompressed with FlateDecode.

6. **Scrubs metadata** — Document metadata is automatically cleaned (see below).

***

## Metadata Scrubbing

Every redaction automatically scrubs document metadata. This is not optional — metadata often contains sensitive information that authors don't realize is embedded.

**What gets removed:**

* Author name
* Creator application
* Edit history
* Comments and annotations

**What gets replaced:**

* `/Producer` → `"Forme"`
* `/ModDate` → current timestamp

***

## Three Ways to Redact

### 1. Coordinate Regions

Draw precise rectangles over areas to redact. Best for known, fixed layouts where content position is predictable. This is what the dashboard's "Draw" mode uses.

```json theme={null}
{
  "pdf": "<base64>",
  "redactions": [
    {"page": 0, "x": 100, "y": 200, "width": 150, "height": 20}
  ]
}
```

### 2. Text Search

Find text by literal string or regular expression. Best for dynamic content where you know what to redact but not exactly where it appears.

```json theme={null}
{
  "pdf": "<base64>",
  "patterns": [
    {"pattern": "Jane Doe", "pattern_type": "Literal"},
    {"pattern": "\\d{3}-\\d{2}-\\d{4}", "pattern_type": "Regex"}
  ]
}
```

### 3. Presets and Templates

Use built-in presets for common sensitive data types, or save reusable sets of patterns as [redaction templates](/concepts/redaction-templates).

```json theme={null}
{
  "pdf": "<base64>",
  "presets": ["ssn", "email", "phone"],
  "template": "hipaa-patient-record"
}
```

**Available presets:**

| Preset          | Pattern                                      |
| --------------- | -------------------------------------------- |
| `ssn`           | US Social Security Numbers (XXX-XX-XXXX)     |
| `email`         | Email addresses                              |
| `phone`         | US phone numbers                             |
| `date-of-birth` | Date patterns (MM/DD/YYYY, YYYY-MM-DD, etc.) |
| `credit-card`   | Credit card numbers                          |

All three methods can be combined in a single request.

***

## Verifying Redaction

After redacting a PDF:

1. Open the redacted PDF in **Chrome** (not macOS Preview)
2. Try to select text in the redacted areas
3. If the redaction worked, there will be nothing to select — the text no longer exists

<Note>macOS Preview may show a text cursor in redacted areas. This is a rendering artifact — the text is actually removed. Always verify in Chrome or Adobe Acrobat.</Note>

***

## Known Limitations

* **WinAnsi encoding only**: Text search and pattern matching works on standard Western-encoded text (WinAnsi/Windows-1252). CJK, Arabic, and other non-WinAnsi encoded text cannot be found by text search — use coordinate redaction instead.
* **Images and vector graphics**: In v1, images and vector graphics within redacted regions are covered by the visual overlay but not removed from the content stream. True image redaction is planned for a future release.
* **Maximum 50 patterns per request**: Keep the total number of patterns (including those expanded from presets and templates) under 50.

***

## Compliance Use Cases

* **HIPAA**: Redact patient names, SSNs, dates of birth, and medical record numbers before sharing
* **GDPR**: Remove personally identifiable information from documents shared with third parties
* **FOIA**: Redact exempted information from public records requests
* **Legal Discovery**: Protect privileged information in document productions
* **Internal Audit**: Remove sensitive details before sharing reports across departments

***

## Related

* [Redact API](/api-reference/redact) — endpoint reference with code examples
* [Redaction Templates](/concepts/redaction-templates) — saved pattern sets
* [Bring Your Own UI](/guides/bring-your-own-ui) — building a custom redaction interface