Redaction API
Java
Philter
Turnkey, self-hosted PII redaction with a clean API. Drops into any pipeline that needs sensitive data removed from text — and runs entirely inside your cloud.
Star 41 Deploy →Your Cloud. Your Data.
Zero-Trust PII Redaction.
Open source PII redaction that runs entirely inside your cloud — for healthcare, finance, legal, and government workloads where a leak isn't an option.
In production since 2017. Or explore the toolkit ↓
Trusted in
- Healthcare
- Finance
- Legal
- AI & Machine Learning
- Government
- Contact Centers
- Insurance
- AI Training Data
- Education
The World-Class Open Source Toolkit for PII Privacy
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 and business-friendly Apache license and developed in the open on GitHub.
Core redaction
The engine and API that find and redact PII in text.
AI models & LLM guardrails
Trained models and drop-in proxies for AI workloads.
AI Models & Server
Python
PhEye
The trained AI and NLP models that find PII and PHI in text, plus the service that hosts them. Designed to plug directly into Phileas and Philter.
Star 1LLM proxy
Java
Philter AI Proxy
Drop-in proxy that redacts PII and PHI before prompts reach LLM providers like OpenAI and Anthropic Claude.
Star 2Discovery & monitoring
Find where PII lives and watch where it flows.
Discovery
Java
Phinder
High-speed discovery scanner that crawls files and storage to map where sensitive information actually lives across your environment.
Star 1Monitoring
Go
Phield
Intelligent monitoring that tracks PII flow across the organization and alerts on suspicious activity or unusual trends.
Star 2Review, policy & operations
Human review, policy authoring, benchmarking, and privacy analytics.
Benchmarking
Go
Philter Scope
Standalone audit tool that scores redaction policies on precision and recall, so policy changes can be measured rather than guessed at.
Star 1Human 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 1Differential privacy
Python
Philter Diffuse
Privacy-first analytics that applies differential privacy to PII counts, preserving statistical utility without exposing individuals.
Star 1Policy editor
JavaScript
Redaction Policy Editor
Web console that lets non-technical users build and deploy redaction rules through a visual, no-code interface.
Star 1Not sure which one to start with? Walk through the PII redaction journey →
Client SDKs for Java, .NET, and Go are available alongside the rest of the toolkit at github.com/philterd.
Privacy AI
Specialized Large Language Models trained exclusively for high-accuracy PII discovery, classification, and redaction. An effective PII strategy combines pattern matching for structured data with AI for the unstructured text where rigid patterns fall short.
Pattern-based identification
Predefined character sequences detect structured data like credit-card numbers, SSNs, and email addresses. Fast, predictable, and lightweight to run — but rigid in the face of unstructured text.
LLM-based identification
Trained models read the linguistic context and intent around sensitive data. Highly accurate, adaptable across languages, and effective on the unstructured text where patterns alone fail.
Hybrid by design
Pattern matching provides a high-speed foundation; LLMs add the intelligent oversight unstructured text demands. The two methods complement each other inside every Philterd deployment.
Curious how the models are trained and benchmarked? Read about our hybrid approach →
The Three Pillars of Privacy
Everything we build sits on top of three commitments: data stays with you, the source code stays open, and the AI underneath stays purpose-built for the job.
Data Sovereignty
Philter and the rest of the Philterd toolkit run inside your cloud. Your data never leaves your perimeter, never reaches a third-party API, and never lands in someone else's logs.
Open Source Integrity
Transparency is the only way to verify privacy software. Our core engine is Apache 2.0 licensed — your engineers can read every line, audit every decision, and extend the stack on their own terms.
Purpose-Built AI
Generic LLMs make poor privacy filters. We train and ship specialized NLP and deep-learning models built specifically for PII and PHI detection — accurate, tunable, and operationally affordable at scale.
Compliance and Trust
Philterd provides a zero-trust architecture for HIPAA, GDPR, and CCPA compliance. The discovery engine operates entirely within your infrastructure — 100% data sovereignty, no external API dependencies, no third-party data training.
To satisfy HIPAA Safe Harbor requirements, we pair high-speed pattern matching for structured identifiers with specialized AI models for everything else, capturing all 18 protected identifiers under 45 CFR § 164.514. Healthcare and life-sciences organizations can automate de-identification across massive datasets while preserving the utility the data needs for research and innovation.
Need help mapping your HIPAA, GDPR, or PCI posture to a Philter deployment? Get an architecture review → · See the full compliance breakdown →
Three ways to get started
Same redaction engine, three paths. Pick the one that fits your team.
Free forever
Open Source
$0 · Open source
Run the entire Philterd toolkit yourself. Full source on GitHub — no license keys, no usage caps, no commercial review.
- All 9 tools, full source code
- User's guides and reference docs
- Community support via GitHub issues
- Every update and new release
Best for: Engineering-led teams who want to own every layer.
Per-hour billing
Philter on Cloud Marketplaces
From $0.49/hr · ~$360/mo
Deploy Philter — our turnkey redaction API — into your VPC from the AWS, Google Cloud, or Azure marketplace. Production-ready in minutes; billed through your existing cloud account. The other Philterd tools are not yet on the cloud marketplaces.
- One-click Philter deploy into your VPC
- Vendor-supported updates
- Unified billing via your cloud provider
- No procurement contract required
Best for: Teams that want production-ready Philter without managing builds or ops.
Deploy in 5 minutes
Available on AWS, Google Cloud, and Azure. AWS Marketplace list price shown — see the full TCO comparison →
Engagement-based
Engaged
Custom
Work directly with the people who built the toolkit. Custom NLP models, privacy architecture, embedded engineering, and production deployment with full handoff.
- Custom NLP model training
- Privacy architecture review
- Embedded engineering
- Deployment + knowledge transfer
Best for: Healthcare, finance, and government workloads with custom requirements.
From the blog
Practical posts on PII redaction, AI privacy, and self-hosted compliance.
· Philter, Redaction
Introducing Arbiter: Human-in-the-Loop PII Redaction
Automated redaction handles most of the volume; humans handle the last few percent that automation can't. Arbiter is the open source review surface that bridges the two — built on Philter, designed for AI training data and regulated everyday workflows.
Read post →· AWS, Philter
The TCO of "Free" Cloud PII Redaction: AWS Comprehend, Google DLP, vs Self-Hosted at Scale
Per-character SaaS pricing looks cheap at demo scale and gets eye-watering at production scale. A worked-example TCO comparison: AWS Comprehend, Google Cloud DLP, and self-hosted Philter on the marketplace.
Read post →· Redaction, Philter
What is PII? A Practical Guide for Engineers and Compliance Teams
PII is the term everyone uses and few people define the same way. A practitioner's guide to what counts as PII, how to find it in real data, and how to handle it without breaking everything downstream.
Read post →For integrators & system builders
Building for someone else?
Philter is the redaction layer integrators bundle into client deliverables. Deploys in the client's cloud, operated by you, no per-seat license, no vendor sub-license to negotiate. Reference architectures for the patterns clients actually buy.
New · Open Source
Introducing Arbiter
Arbiter is the newest addition to our open source toolkit for PII privacy — a human-in-the-loop review surface for redaction pipelines. Reviewers see every detection in context, accept or override automated decisions, and apply structured exemption codes that flow into your audit trail. Built on Philter; designed for AI training-data prep and regulated everyday workflows.
Consulting Services
Accelerate compliance and reduce leak risk by working directly with the creators of Philter. We design, build, and deploy the privacy infrastructure your team will own — not a black box you have to renew every year.
Privacy Architecture
We design end-to-end PII protection for your cloud and AI workloads — data flows, redaction layers, audit trails, and the guardrails that keep them aligned with HIPAA, GDPR, and CCPA.
Custom NLP Models
Off-the-shelf models miss the entities that matter most in your domain. We train specialized PII/PHI detectors on your data, evaluated against precision and recall you can measure.
AI Guardrails
Pre-launch privacy review of generative AI and RAG systems. We trace PII through prompts, retrieval context, tool calls, logs, and vector stores — then ship the redaction and policy changes.
See all consulting services → · Have a specific project in mind? Schedule a 30-min call →
Ready to lock down your data?
Tell us about your stack and the privacy problems you're trying to solve. We'll get back to you within one business day.