BleachPDF vs Philter

BleachPDF is a free desktop utility for Linux and macOS that redacts sensitive information from PDF files, including scanned pages. It converts each page into an image, applies OCR to locate text you specify, covers matches with black boxes, and writes a new PDF. The resulting file contains images only, so it has no hidden text layer that could reveal redacted wording through copying and pasting. Matching can use exact text or more complex patterns, including case-insensitive rules and digit patterns. Its command line accepts a folder or file pattern for batch processing. After redaction, BleachPDF rescans the output; if matching text is still exposed, verification fails and processing stops. It runs locally without uploading documents. Installation uses pip and requires Tesseract, with OCR language selection such as eng or eng+kor. Handwriting, unusual fonts, poor scans, and tiny dense text can cause recognition errors, so manual checking is advised.

Philter is open-source software for finding and redacting personally identifiable information and protected health information in text. For detected entities, users can choose to mask, encrypt, replace with synthetic values, remove, or pass them through. Policies, custom dictionaries, and identifier patterns such as medical record numbers and transaction IDs let teams configure what to detect and how to handle it. General Purpose, Healthcare, and COVID-19 NLP lenses address different types of text. Philter provides an HTTP REST API, a Java SDK, and an OpenAPI specification for generating clients in other languages. It can run in a private environment or through AWS, Google Cloud, and Microsoft Azure marketplaces. The maker says text stays in the customer’s environment, including firewalled or air-gapped deployments. Redaction requests are recorded in a tamper-evident, hash-chained audit log that can be queried and exported to CSV. Detection is probabilistic, so results should be checked against an organization’s own data before production use. The open-source toolkit has community support; commercial licenses include direct support.