Philterd

Contact Us

Tell us about your stack and the privacy problems you're trying to solve. We typically respond within one business day.

Prefer email? support@philterd.ai

Please do not enter PII or PHI in this form. If you need to share an example, use a sanitized one.

Open source & self-hosted

Open Source PII Redaction Software

Open source PII and PHI redaction you self-host. Apache-2.0 licensed and free to run on your desktop or in your cloud. Helps meet HIPAA and GDPR compliance.

The Open Source PII Toolkit

A complete stack for finding, redacting, monitoring, and auditing sensitive data, from low-level libraries to turnkey services. Each project is released under the permissive, business-friendly Apache License and developed in the open on GitHub.

Core redaction

The engine and API that find and redact PII in text.

Desktop app .NET

Philter Desktop

Offline Windows desktop app that redacts PII from PDF, Microsoft Word, and text files entirely on your own machine, using the same policy engine as Philter. In active development.

Star 1
Learn more → GitHub →

AI models & LLM guardrails

Trained models and drop-in proxies for AI workloads.

MCP server Python

Philter MCP

MCP server that exposes Philter's PII and PHI redaction as tools for Claude Desktop, Claude Code, Cursor, and other MCP-aware clients. Redact inside the agent's tool loop, with no integration code.

Star 1
Learn more → GitHub →

Discovery & monitoring

Find where PII lives and watch where it flows.

Review, policy & operations

Human review, policy authoring, benchmarking, and privacy analytics.

Human review Java

Arbiter

Human-in-the-loop PII redaction. Search, review, and override automated detection decisions with structured exemption codes. Built for AI training-data prep and regulated everyday workflows.

Star 1
Learn more → GitHub → Docs →
Query language Java

PhiSQL

Declarative query language for PII operations. Write readable redaction policies as code that compile to the standard Phileas JSON schema.

Star 1
Learn more → GitHub →
Policy routing Java

Philter Router

The routing front door for Philter. Selects the redaction policy and engine for each file from its content type, filename, directory, and an optional local-LLM classification, with a mandatory default so no file is routed around redaction.

Star 1
Learn more → GitHub → Docs →

Not sure which one to start with? Walk through the PII redaction journey → · See how they all connect →

Which open source Philterd tool do I need?

Every tool in the Philterd toolkit is open source and free to run. Start from what you're trying to do, and each path maps to the tools that solve it.

I want to redact PII

Pick the surface that matches where the text lives: an API, an embedded library, an LLM gateway, or files at rest.

  • Philter → Self-hosted redaction API. Drops into any HTTP-based pipeline.
  • Phileas → The same engine as a library in Java, Python, and .NET. No service hop.
  • Philter AI Proxy → Drop-in proxy for OpenAI and Anthropic. One URL change.
  • Philter Router → Routes files to the right policy and Philter engine. Watches folders or exposes an HTTP API.

I want to find and watch PII

Map where PII already lives, then watch how it moves through the systems you care about.

  • Phinder → Discovery scanner that crawls files and storage to find PII at rest.
  • Phield → Flow monitoring that tracks how PII moves and alerts on suspicious activity.

I want to author, review, and measure policies

Build the policy, override what the system gets wrong, and measure how well it works over time.

Read it, run it, own it

Philterd builds open source software for finding and redacting PII and PHI in text. Every tool is released under the permissive, business-friendly Apache License, Version 2.0, and developed in the open on GitHub. You can read the source, run it for free, and self-host it inside your own cloud or data center. See PHI redaction for the HIPAA-specific workflow.

Why open source, self-hosted redaction

Redaction decides your compliance boundary, and the boundary is what an auditor examines. If sensitive text has to leave your network to be redacted by a hosted service, the exposure has already happened. The open source, self-hosted approach removes that problem at the root:

  • Your data never leaves your perimeter. Philter runs inside your VPC or on-premises, so customer names, Social Security numbers, medical record numbers, and account IDs are redacted before anything crosses the wire. This is what keeps HIPAA, GDPR, and PCI scope defensible.
  • No vendor lock-in. Apache-2.0 means no license keys, no per-seat fees, and no commercial review. Run it on AWS, Google Cloud, Azure, on-premises, or air-gapped.
  • Auditable by design. The detection logic is purpose-built NLP and pattern matching that you can read, test, and version, not a black box. Policies are versioned artifacts, so “what did we redact, and how, on this date” is answerable with a diff.
  • Free to run. The full toolkit is free under the open source tier. Commercial paths exist for teams that want one-click marketplace deploys or hands-on engineering, but the code is never gated.

Apache-2.0 licensed

Every Philterd project is released under the Apache License, Version 2.0. You are free to use, modify, and distribute it under the terms of that license, with no per-seat fees and no usage caps. See the full Philter license for details, and browse all of the source on the Philterd GitHub organization .

Compare and explore

Weighing your options? Start with the overview of the best PII redaction software .

See how Philter compares to other tools: Microsoft Presidio , AWS Comprehend , Google Cloud DLP , Private AI , and Skyflow .

Or see it by industry: healthcare , finance , legal , government , and insurance .

New to redaction? Start with what PII is , running detection on your own hardware , and writing your first redaction policy .

Frequently asked questions

If something here isn’t covered, get in touch and we’ll answer.

Is all of Philterd's software really free and open source?
Yes. The full toolkit is on GitHub under the Apache License, Version 2.0. There are no license keys, no usage caps, and no commercial review. Self-host it on whatever infrastructure you want. Philterd earns revenue from cloud-marketplace deployments and engaged consulting, not from gating the code.
Can I self-host PII redaction in my own cloud?
Yes, and that is the point. Philter and the rest of the toolkit run inside your own VPC, on-premises, or air-gapped environment, so sensitive text is redacted before it ever leaves your network. Nothing is sent to a vendor in order to be redacted.
What license is the software under?
The Apache License, Version 2.0, a permissive and business-friendly open source license.