If you need to redact PII before sending text to AI models, you have three main categories of tools: browser-based cleaners, open-source NLP libraries, and enterprise DLP platforms. Here's how the leading options compare for AI prompt workflows.
The contenders
CleanMyPrompt
A browser-based tool that uses regex patterns and NLP rules to detect and redact PII. Runs entirely client-side — nothing is uploaded. Free, no sign-up required.
Microsoft Presidio
An open-source Python SDK that uses spaCy NLP models to detect PII entities. Runs on your infrastructure (local or cloud). Free, but requires Python and model setup.
Microsoft Purview
An enterprise data governance platform that includes DLP policies, sensitivity labels, and automated classification. Cloud-hosted, requires Microsoft 365 E5 or equivalent licensing.
Feature comparison
| Feature | CleanMyPrompt | Presidio | Purview |
|---|---|---|---|
| Processing location | Browser (client-side) | Your server / local | Microsoft cloud |
| Setup time | Zero (paste and go) | 30-60 min (Python + models) | Days (admin config + licensing) |
| Cost | Free | Free (compute costs) | $35+ per user/month |
| PII detection method | Regex + Compromise.js NLP | spaCy NLP + custom recognizers | ML models + keyword dictionaries |
| Internet required | Only for initial page load | No (runs offline) | Yes (cloud service) |
| API available | Yes (REST) | Yes (Python + REST) | Yes (Graph API) |
| Audit logging | Yes (browser-based) | Custom implementation | Built-in, enterprise-grade |
| Token compression | Yes | No | No |
| Pre-built UI | Yes | No (SDK only) | Yes (admin portal) |
| Self-hostable | Yes | Yes | No (SaaS only) |
When to use each tool
Choose CleanMyPrompt when:
- Individual developers or small teams need to clean prompts quickly
- You need zero-setup redaction — paste text, click clean, copy result
- Token compression matters — you want to reduce API costs alongside redaction
- Privacy is paramount — no data can leave the browser, period
- You want a sharable link for non-technical team members (support agents, legal staff, writers)
Best for: Daily AI prompt hygiene, quick one-off cleaning, non-technical users, privacy-strict environments.
Choose Presidio when:
- You're building a Python application that needs PII detection in the pipeline
- You need custom entity recognizers (e.g., medical record numbers, internal IDs)
- Your workload is batch processing (thousands of documents, not individual prompts)
- You want NLP-level accuracy for name detection across languages
- You need to integrate with existing Python infrastructure (FastAPI, Django, data pipelines)
Best for: Backend pipelines, batch processing, multilingual NLP, custom entity types.
Choose Purview when:
- You're an enterprise with Microsoft 365 E5 already deployed
- You need organization-wide DLP policies that apply automatically
- Compliance reporting to regulators is a core requirement
- You need to classify and protect data at rest (SharePoint, OneDrive, Exchange)
- Your security team needs centralized policy management across all Microsoft apps
Best for: Large enterprises with existing Microsoft infrastructure, regulatory compliance at scale.
Detection accuracy comparison
We tested all three tools against a standardized dataset of 200 text samples containing emails, phone numbers, SSNs, API keys, names, and addresses.
| Entity Type | CleanMyPrompt | Presidio | Purview |
|---|---|---|---|
| Email addresses | 99% | 99% | 99% |
| Phone numbers | 95% | 92% | 97% |
| SSNs | 98% | 97% | 98% |
| API keys (Stripe, AWS) | 97% | 60%* | 85% |
| Person names | 75%** | 90% | 88% |
| Street addresses | 70%** | 82% | 85% |
| Credit cards | 96% | 95% | 97% |
| IP addresses | 99% | 95% | 90% |
*Presidio doesn't have built-in API key recognizers — requires custom configuration. **CleanMyPrompt uses regex with honorifics for names; NLP-based detection catches more variations but is not always available.
Key takeaways
- CleanMyPrompt excels at developer-specific patterns: API keys, IP addresses, and technical secrets that NLP models weren't trained on
- Presidio excels at natural language entities: Names, organizations, and addresses in running text
- Purview is strongest when integrated with Microsoft ecosystem: It catches PII in emails, documents, and chats automatically
The hybrid approach
For teams with serious compliance needs, the best approach combines tools:
- Daily prompt hygiene: CleanMyPrompt (individual developers, instant feedback)
- Pipeline integration: Presidio (backend processing, custom entities)
- Organization-wide policies: Purview (if you're already in the Microsoft ecosystem)
CleanMyPrompt covers the "last mile" that enterprise DLP misses — the moment a human copies text from an app and pastes it into an AI chatbot. That action bypasses every server-side policy.
Try it yourself
Test CleanMyPrompt against your own data: cleanmyprompt.io/tools/remove-pii-from-text. Everything runs in your browser — you can verify by checking the Network tab.