Fiddler AI vs Lakera
Both are guardrails & safety tools. Here is how they actually differ on price, billing model and deployment.
Fiddler AI
Guardrails powered by purpose-built models that run inside your own VPC rather than calling an external API. That architecture removes the per-check inference cost that every judge-based guardrail quietly adds to your model provider bill.
Lakera
The best-known prompt injection defence API, acquired by Check Point in September 2025 for a reported $300M. Still developed by the original Zurich team, but sales now run through Check Point enterprise procurement.
| Fiddler AI | Lakera | |
|---|---|---|
| Category | Guardrails & Safety | Guardrails & Safety |
| Our rating | 4/5 | 4/5 |
| Starting price | Not published | Not published |
| Billing meter | No usage metering | No usage metering |
| Free plan | No | Yes |
| Free self-hosting | No or paid tier only | No or paid tier only |
| Best for | Regulated enterprises that need guardrails running inside their own environment, particularly those already running predictive ML alongside LLM systems, and who can work with enterprise procurement. | Teams that want managed, low-latency prompt injection defence with enterprise support and are comfortable with a proprietary API and an enterprise sales process. |
Our verdict on Fiddler AI
Fiddler has made one architectural decision that sets it apart and it is the right one. Its guardrails run on purpose-built models - branded Fiddler Centor Models, previously Trust Models - that execute entirely within your own cloud or VPC, covering Safety, PII and Faithfulness. Almost every competitor implements guardrails by calling an LLM to judge each request, which means every check is a billable inference call landing on your foundation model provider's invoice, plus latency in the request path. Fiddler calls this the Trust Tax, and while that is marketing language the underlying criticism is accurate and it is the same cost trap we have flagged on NeMo Guardrails and on LLM-as-judge evaluation generally. Solving it with small purpose-trained models running in your environment is a genuinely better design, and it improves the privacy posture at the same time. Two caveats temper it. Nothing is published on pricing. And the VPC deployment that constitutes the main selling point starts at Enterprise, with the Developer tier running on Fiddler's cloud only - so the entry tier does not give you the thing that makes the product interesting.
Full Fiddler AI review →Our verdict on Lakera
Lakera is the strongest managed prompt injection defence available and the acquisition has not obviously damaged it. Check Point acquired the company in September 2025 in a deal reported around $300 million, taking Lakera Guard, Lakera Red and the Gandalf dataset into its AI security platform, and basing its Global Center of Excellence for AI Security on the Zurich team. That team still maintains the detection models, which is the outcome you want from an acquisition and is notably better than what happened to Helicone. The technical case rests on data. Lakera's models learn from a very large stream of adversarial prompts, drawn partly from the Gandalf community game, and that corpus is genuinely hard for a competitor to replicate. Vendor figures of 98%+ detection at sub-50ms latency with under 0.5% false positives are strong if accurate, though we could not verify them. The friction is commercial - nothing is published on pricing, and buying now means Check Point enterprise procurement rather than a credit card.
Full Lakera review →Frequently Asked Questions
What is the main difference between Fiddler AI and Lakera?
Fiddler AI: Regulated enterprises that need guardrails running inside their own environment, particularly those already running predictive ML alongside LLM systems, and who can work with enterprise procurement. Lakera: Teams that want managed, low-latency prompt injection defence with enterprise support and are comfortable with a proprietary API and an enterprise sales process. Both sit in Guardrails & Safety, so the decision usually comes down to billing model and deployment rather than raw capability.
Which is cheaper, Fiddler AI or Lakera?
It depends entirely on your workload shape, because they meter differently - Fiddler AI bills on no usage metering and Lakera bills on no usage metering. Published starting prices are Not published and Not published respectively, but those numbers are not comparable until you apply them to the same traffic. Use our cost calculator to model both against your own request volume and span count.
Can I self-host Fiddler AI or Lakera?
Fiddler AI: No or paid tier only. Lakera: No or paid tier only. Free self-hosting means no licence fee, not no cost - you still own the infrastructure, upgrades and on-call.