Free
Perfect for testing and side projects.
- Up to 100 requests per month
- 1 API Key
- All detection features
- Ultra-low latency lookup (< 50ms)
- Monthly blocklist updates
- Community support
Pro
For indie hackers and growing projects.
- Up to 10,000 requests per month
- Unlimited API Keys
- All detection features
- Ultra-low latency lookup (< 50ms)
- Real-time blocklist updates
- Email support
Scale
For production apps and scaling startups.
- Up to 50,000 requests per month
- Unlimited API Keys
- All detection features
- Ultra-low latency lookup (< 50ms)
- Real-time blocklist updates
- Custom blocklist & allowlist
- Priority Email support
Custom
For large scale platforms and enterprise compliance.
- Custom volume (> 250k/mo)
- Dedicated Discord/Slack channel
- 99.99% Uptime SLA
- Custom threat feeds
- On-Prem / Self-Host License
Prefer Self-Hosting?
Our core engine is 100% open source. Great for local development, testing, and hobby projects. For production apps, use our hosted API to get automated, daily-synchronized threat blocklists with zero maintenance.
Frequently Asked Questions
Why use the Hosted API instead of self-hosting the open-source library?
Self-hosting is great for local development. However, spam networks spin up new disposable domains every day. The Hosted API syncs these updates automatically in the background, whereas the open-source package requires manual server restarts and package redeployments to update its data.
Does using this API slow down my user signup form?
No. Our lookups run entirely in-memory and respond in under 50ms. It is designed to be completely invisible to your users and has zero noticeable impact on your registration form conversion rates.
Do you store or log my users' email addresses?
No. Your privacy and security are paramount. Email addresses are processed purely in-memory to perform checks and are never written to our disks or databases. We only log anonymous metrics (timestamp and check outcome) to calculate your monthly usage.
What happens if I hit my plan's monthly request limit?
We never want to break your production signup forms. If you approach your limit, we'll send you email alerts and grant a grace period. By default, you can enable soft limits (pay-as-you-go for extra lookups) on your dashboard so your service is never interrupted, or lock it to a hard limit to protect your budget.
Can I configure custom block lists?
Yes! On the Scale plan, you can add custom domains to your dashboard allowlist (to bypass risk checks for trusted partners) or blocklist (to block competitors) without making any changes to your code.
Do you support custom SLAs or dedicated support channels?
Yes! On our Custom plan, we offer a signed 99.99% Uptime SLA, customized volume limits, and a dedicated Slack or Discord channel for direct, priority developer support.
Can I run SignGuard on-premise for strict compliance?
Yes, we offer on-premise self-hosting licenses for enterprise compliance on the Custom plan, allowing you to run SignGuard directly on your own secure cloud environment (AWS, GCP, or bare metal).