ShieldLabs vs Castle
Updated September 2026
Looking for a Castle alternative? ShieldLabs gives enterprise-level functionality without enterprise pricing, with ready-made detection and investigation of users, visitors, devices and IP addresses, and ready-made account sharing and multi-accounting detection, from 99 USD a month for 25,000 identifications. Castle scores risk at the user level only, with no risk level for visitors, devices or IP addresses, and starts at 200 USD a month for 40,000 checks.
How ShieldLabs compares to Castle
| Capability |  |  |
|---|---|---|
| Overall | ||
| Overall score | 9.7 out of 10 | 9.2 out of 10 (ShieldLabs leads) |
| Getting started | ||
| Integration time | About 5 minutes | Hours to days (ShieldLabs leads) |
| Public pricing and self-serve | Public prices, start without a sales call | Public prices, self-serve except Enterprise (comparable) |
| Ease of use | Results in the analytics dashboard with nothing to set up | Rules you configure yourself (ShieldLabs leads) |
| Fit from startup to enterprise | Enterprise-level functionality on every plan, for businesses of all sizes | The querying API, SSO and long retention on Enterprise, from 4,000 USD a month (ShieldLabs leads) |
| Documentation and SDKs | Public docs, client and server SDKs | Public docs, client and server SDKs (comparable) |
| API and webhooks | On every plan, including Free | On every plan, including Free (comparable) |
| Platform coverage | Web and mobile web | Web, native iOS, Android, React Native and Flutter (comparable) |
| Platform flexibility | Ready-made detection, nothing to configure | Rules you configure yourself (ShieldLabs leads) |
| Detection | ||
| Identification accuracy | 99.9%, network and device intelligence | Device intelligence, with partial network coverage (ShieldLabs leads) |
| How the accuracy figure is checked | Published method: what is collected, how the score is built, 1,511 automated tests, audited on more than a million requests | Not published (ShieldLabs leads) |
| Risk signal detection accuracy | 99.9%, network and device intelligence | Device intelligence, with partial network coverage (ShieldLabs leads) |
| Bot and automation detection | Bots, automation and AI agents | Bots and automation, no AI agents (ShieldLabs leads) |
| Breadth of the signal set | 300+ risk signals | A named signal list, with no count published (ShieldLabs leads) |
| Local IP detection | Ready-made, with its country | Not offered (ShieldLabs leads) |
| Geolocation accuracy | Location checked against the local IP and network characteristics, not the public IP alone | From the public IP (ShieldLabs leads) |
| Multi-accounting detection | Ready-made, no rules to configure | Rules you configure yourself (ShieldLabs leads) |
| Account sharing detection | Ready-made, no rules to configure | Rules you configure yourself (ShieldLabs leads) |
| Account takeover detection | Ready-made, no rules to configure | Rules you configure yourself (ShieldLabs leads) |
| Impossible travel detection | Ready-made, no rules to configure | Rules you configure yourself (ShieldLabs leads) |
| Decision and analytics | ||
| Fit to the job | A finished verdict for each detection | Rules you configure yourself (ShieldLabs leads) |
| Risk signal scoring | Ready-made weights for every signal | A machine-learning black box, weights not published (ShieldLabs leads) |
| Why a visit was flagged | Every signal that fired, with its weight | The signals that fired and a score, with no weights (ShieldLabs leads) |
| Cost of a false positive | A ready verdict with every reason shown | A ready verdict with every reason shown (comparable) |
| Analytics a non-engineer can read | Traffic, risk and events ready to read | An overview of login and registration events, and an events explorer you group and filter, over 3 or 7 days of data (ShieldLabs leads) |
| Latency and real-time decisioning | About 300 milliseconds | About 350 milliseconds (ShieldLabs leads) |
| Decision Risk | Trusted, Suspicious or Dangerous for visitors, users, devices and IPs | User-level scores only, no risk level for visitors, devices or IPs (ShieldLabs leads) |
| Traffic-quality scoring | Ready-made | Not offered (ShieldLabs leads) |
| Traffic source | Channel and full UTM | Not offered (ShieldLabs leads) |
| History API | On every plan, for every identification | Their querying API sells only on an enterprise contract (ShieldLabs leads) |
| Pricing | ||
| Free tier | 5,000 identifications, one time | 1,000 Risk API calls a month (comparable) |
| Entry price | From 99 USD a month, 25,000 identifications | 200 USD a month, 40,000 checks (ShieldLabs leads) |
| Price at 25,000 identifications a month | 99 USD a month, 2x cheaper | 200 USD a month (ShieldLabs leads) |
| Price at 150,000 identifications a month | 399 USD a month, 1.9x cheaper | 750 USD a month (ShieldLabs leads) |
| Price at 500,000 identifications a month | 999 USD a month, 2.5x cheaper | 2,500 USD a month (ShieldLabs leads) |
| Price per identification | From 0.00396 USD down to 0.00200 USD, included in the plan price | 0.005 USD per check, inside a 200 USD monthly minimum (ShieldLabs leads) |
| Plans and support | ||
| Features on every plan | Every feature on every plan, including Free | The querying API, SSO and custom roles on Enterprise, 3 custom metrics on Free and Pro (ShieldLabs leads) |
| Data retention | 90 days on every plan | 3 days on Free, 7 days on Pro, longer on Enterprise (ShieldLabs leads) |
| API requests per second | From 5 to 15 RPS | 1 on Free, 5 on Pro, no limit on Enterprise (comparable) |
| Uptime SLA | 99.9% on Scale, self-serve | On an enterprise contract only, from 4,000 USD a month (ShieldLabs leads) |
| Support | Chat and email on every plan, including Free | Documentation on Free, chat and email from Pro, integration help on Enterprise (ShieldLabs leads) |
Every competitor cell was checked on their public website and docs, and in our own testing, in September 2026. How ShieldLabs measures 99.9% accuracy
Why choose ShieldLabs
Ready-made detection, no rules to configure
Multi-accounting, account sharing, account takeover and impossible travel come ready, with Medium or High confidence and no rules to configure. Castle publishes no account sharing signal, and with Castle you configure the rules yourself.
Enterprise quality at a lower price
More mature functionality at a lower price: from 99 USD a month for 25,000 identifications, and the price per identification drops as your traffic grows. Castle charges its 200 USD monthly minimum for the same 25,000, and a flat 0.005 USD per check on its public plans.
Transparent scoring
ShieldLabs publishes the weight of every risk signal, so you can trace every score back to what raised it. Castle scores with machine learning and publishes no weights, a black box that can raise false positives you cannot explain.
Risk analytics and investigation
Investigate visitors, devices and IPs, each rated Trusted, Suspicious or Dangerous, and see the overall risk across all your traffic and by source, channel and UTM. Castle gives an events explorer you group and filter yourself, keeps 3 or 7 days of data on its self-serve plans, and has no traffic source view.
Switch to a Castle alternative without a migration
Both install side by side without conflicting. Add ShieldLabs on the free tier alongside your current Castle setup, compare the data for a week, see the quality for yourself, and switch to ShieldLabs when you are ready.
- 01
Install the ShieldLabs snippet next to Castle in about five minutes.
- 02
Collect 5,000 free identifications on the same traffic.
- 03
Detect risky visitors and users, and compare them with what Castle flags.
- 04
Move to ShieldLabs and prevent abuse of your product.
Frequently asked questions
- What is the best Castle alternative?
- ShieldLabs gives enterprise-level functionality without enterprise pricing, with ready-made detection and investigation of users, visitors, devices and IP addresses, and ready-made account sharing and multi-accounting detection, from 99 USD a month for 25,000 identifications. Castle scores risk at the user level only, with no risk level for visitors, devices or IP addresses, and starts at 200 USD a month for 40,000 checks.
- How is ShieldLabs different from Castle?
- Multi-accounting, account sharing, account takeover and impossible travel come ready, with Medium or High confidence and no rules to configure. Castle publishes no account sharing signal, and with Castle you configure the rules yourself.
- How much does ShieldLabs cost compared to Castle?
- ShieldLabs costs 99 USD a month for 25,000 identifications, 399 USD a month for 150,000 identifications, 999 USD a month for 500,000 identifications, with 5,000 identifications free to start. Castle: 200 USD a month at 25,000; 750 USD a month at 150,000; 2,500 USD a month at 500,000.
- Can ShieldLabs run alongside Castle?
- Both install side by side without conflicting. Add ShieldLabs on the free tier alongside your current Castle setup, compare the data for a week, see the quality for yourself, and switch to ShieldLabs when you are ready.
Ready to get started?
Start free with 5,000 identifications. Add the snippet once, and the analytics dashboard fills in from your first visitor.