Fiddler AI
Fiddler AI, Inc.
Observability, evaluation and guardrails for predictive models and LLM agents, with guardrails that run inside your own cloud
Last checked October 15, 2026Quick facts: Fiddler AI is an AI compliance vendor founded in 2018 and headquartered in Palo Alto, United States. The vendor publicly documents coverage for SOC 2, HIPAA, EU AI Act, and NIST AI RMF. Pricing is tiered. Profile last checked October 15, 2026; sources are cited at the bottom of this page.
About Fiddler AI
Fiddler AI is an observability, evaluation and guardrails platform that now calls itself "the control plane for enterprise AI agents." It was founded in October 2018 by Krishna Gade (CEO), formerly an engineering manager at Facebook, and Amit Paka (COO), and is based in Palo Alto, California. It has raised $100 million; its latest round was a $30 million Series C led by RPS Ventures in January 2026, with Lightspeed Venture Partners, Lux Capital and Insight Partners among the existing investors taking part. Fiddler says its revenue grew more than fourfold in the 18 months before that round. Customers shown on its site include Nielsen, Integral Ad Science, Qualtrics, Thumbtack, LendingPoint, American Family Insurance and the US Department of Energy. The platform covers two kinds of AI. For predictive models, ML Observability tracks performance, drift and data integrity with root-cause analysis, gives global and local explanations, and runs fairness checks such as disparate impact, equal opportunity and demographic parity on structured, text and image models. For LLM applications and agents, it ingests OpenTelemetry traces (with integrations for LangGraph, LangChain, Strands Agents, Google ADK, Claude Code and LiteLLM), scores them with 80+ built-in metrics, custom evaluators or your own LLM judge, and runs experiments against golden datasets. Its Guardrails, powered by Fiddler's own Centor models, screen prompts and responses for hallucinations (faithfulness), toxicity, jailbreaks, prompt injection and 35+ types of PII and PHI. Fiddler says enforcement takes under 80 ms and runs inside the customer's cloud or VPC with no data leaving it. Deployment options are SaaS, VPC, AWS GovCloud and on-premises. **AI compliance coverage** Fiddler's governance features are audit trails that record every decision, action, evaluation and policy outcome, plus executive dashboards. Its governance page names SR 11-7, HIPAA and NAIC, and lists the EU AI Act among relevant policies; its Control Plane FAQ says its audit trails support the NIST AI RMF, ISO/IEC 42001, HIPAA, SR 11-7, NAIC and the EU AI Act. It doesn't publish control mappings, templates or a model inventory for any of them. Fiddler says it has a SOC 2 Type II report and is HIPAA compliant. In 2023 it released Fiddler Auditor, a free LLM red-teaming and robustness library under the Elastic License 2.0, but its last release was in November 2023 and red-teaming isn't part of the current platform. **Who it's for** Enterprises in financial services, insurance, healthcare and government that run predictive models and LLM agents in production and want monitoring, evaluation and runtime guardrails in one place, often inside their own cloud. It is an observability and enforcement layer, not a governance workflow tool: teams that need AI inventories, risk assessments and policy workflows will need a governance platform alongside it.
Featured in
Fiddler AI is ranked in the following independent collections.
Frameworks supported
Regulations, voluntary standards and compliance programs Fiddler AI documents support for on their own materials. Chip shading reflects the strength of the claim, not an independent audit.
Regulation · United States · active
Regulation · EU · Phased — in force; high-risk rules deferred
Voluntary standard · US · voluntary
Voluntary standard · Global · voluntary
Attestations held
Third-party security attestations and certifications Fiddler AI documents on their own materials. These are point-in-time auditor opinions, not regulatory compliance. Always request the current report or certificate directly from the vendor before relying on it.
Attestation · United States (AICPA)
Fiddler AI features
Capabilities Fiddler AI markets publicly. Inclusion means the feature is documented on the vendor's site — not that it's best-in-class. Last checked October 15, 2026.
Model Monitoring
Production monitoring for performance, drift, data quality, and fairness regressions.
Drift Detection
Automated detection of distribution shift, feature drift, prediction drift, and performance degradation in deployed ML/AI models.
Explainability
SHAP, LIME, counterfactual, and feature-importance explanations for model decisions.
Bias & Fairness Testing
Automated statistical testing for disparate impact across protected attributes, with audit-ready reports.
LLM Observability
Logging, tracing, and metrics for LLM applications in production — latency, cost, quality, and error rates across traces and users.
Agent Tracing
End-to-end visibility into multi-step LLM agent runs: tool calls, intermediate reasoning, token usage, latency, and errors at each step.
LLM Evaluation
Systematic testing of LLM outputs for correctness, relevance, safety, and consistency using automated scorers, rubrics, or human review.
Hallucination Detection
Automated scoring of LLM outputs for factual accuracy and groundedness, typically via retrieval-backed verification or reference comparison.
LLM Guardrails
Runtime input/output filtering for LLMs — PII redaction, toxicity blocking, prompt injection defense, policy enforcement.
Prompt Injection Defense
Detection and mitigation of malicious prompts intended to bypass system instructions or exfiltrate data.
Data Leakage Prevention
Inspection of LLM outputs to block PII, secrets, and regulated data from leaving the boundary.
Policy Enforcement
Mechanism for applying organizational and regulatory policies to AI usage at runtime.
Audit Logging
Tamper-evident logging of governance events (approvals, model changes, policy decisions) required by EU AI Act Article 12 and similar regulations.
Industries served
Integrations
Documented by Fiddler AI in public product materials.
- AWS SageMaker
- Google Vertex AI
- Databricks
- Datadog
- NVIDIA
- Amazon Bedrock
- Azure OpenAI Service
- OpenAI API
- Anthropic API
- LangChain
- LiteLLM
- OpenTelemetry
- AWS GovCloud
Fiddler AI pricing
Three plans: Free (real-time guardrails for hallucinations, toxicity, PII/PHI, prompt injection and jailbreaks, powered by Fiddler's Centor models); Developer at $0.002 per trace (adds unified observability with tests and experiments for agentic and predictive systems, custom evaluators and bring-your-own judge, role-based access control and SSO; SaaS only); and Enterprise, priced by sales (adds enterprise-grade guardrails and scale, SaaS, VPC or on-premises deployment, and a named customer success manager). The pricing page lists no trace or user limits.
Third-party reviews
Publicly cited ratings from independent review platforms. We don't collect reviews ourselves and we don't weight these in our rankings. Low review counts (≤2) are noted so you can decide how much signal to take from them.
G2
4 reviews
Capterra
3 reviews
We publish the cited numbers as-is and do not combine them into an aggregate rating, on this page or in search-result markup.
Pros and cons of Fiddler AI
Pros
- Covers predictive models (drift, explainability, fairness metrics) as well as LLM agents (tracing, evaluation, guardrails) on one platform.
- Published entry pricing: a Free guardrails plan and a Developer plan at $0.002 per trace.
- Guardrails and evaluation models run inside the customer's cloud or VPC, with vendor-stated enforcement latency under 80 ms; VPC, AWS GovCloud and on-premises deployment are offered.
- Audit trails record every decision, action, evaluation and policy outcome; Fiddler has a SOC 2 Type II report and says it is HIPAA compliant.
Cons
- Thin framework support: the EU AI Act, NIST AI RMF and ISO 42001 are named only in passing, with no control mappings, templates or reports described.
- No documented AI model inventory, risk assessment or policy workflow, so it doesn't replace a governance platform.
- The Free plan covers guardrails only; observability, evaluations and SSO start on the Developer plan, and VPC or on-premises deployment requires the quoted Enterprise plan.
- No current red-teaming: its Fiddler Auditor library hasn't had a release since November 2023.
- Few third-party reviews: 4 on G2 and 3 on Capterra as of October 2026.
Alternatives to Fiddler AI
Frequently asked
What is Fiddler AI?+
Fiddler AI is a Palo Alto-based observability, evaluation and guardrails platform for predictive ML models and LLM agents, founded in 2018. It monitors drift, performance and fairness, traces and evaluates agents, and blocks hallucinations, prompt injection and PII leaks at runtime.
Is Fiddler AI a governance platform or an observability tool?+
Mainly an observability and enforcement tool. It produces audit trails and dashboards that support governance reviews, but it doesn't document an AI inventory, risk assessments or policy workflows, so teams that need those use a governance platform alongside it.
How much does Fiddler AI cost?+
Fiddler has three plans: Free (runtime guardrails), Developer at $0.002 per trace (adds observability, evaluations, custom evaluators, RBAC and SSO) and Enterprise, which is quoted and adds VPC or on-premises deployment. The pricing page lists no trace or user limits.
Does Fiddler support the EU AI Act, NIST AI RMF or HIPAA?+
Partly. Fiddler says its audit trails support the NIST AI RMF, ISO/IEC 42001, HIPAA, SR 11-7, NAIC and the EU AI Act, and its guardrails detect PHI for HIPAA use cases. It doesn't publish control mappings or templates for these frameworks.
Has Fiddler AI been acquired?+
No. We found no acquisition of Fiddler as of October 2026. Its most recent financing was a $30 million Series C led by RPS Ventures in January 2026, which took total funding to $100 million.
What are the alternatives to Fiddler AI?+
The closest alternatives in this directory are Arize AI and Arthur, which also cover predictive and LLM monitoring, and Galileo (now Splunk Agent Observability), LangSmith and W&B Weave, which focus on LLM and agent evaluation and tracing.
Sources
- Fiddler AI: Homepage (Control Plane, products, deployment options, partners)
- Fiddler AI: Pricing (Free, Developer at $0.002 per trace, Enterprise)
- Fiddler AI: Fiddler raises $30M Series C (January 27, 2026)
- FinSMEs: Fiddler AI raises $30M in Series C funding (January 2026)
- SiliconANGLE: Fiddler Labs raises $10.2M Series A; founded October 2018 (September 2019)
- Fiddler AI: About (founders, customers)
- Fiddler AI: ML Observability (drift, explainability, fairness)
- Fiddler AI: Guardrails (Centor models, PII/PHI, prompt injection, under 80 ms)
- Fiddler AI: Continuous Evaluations (datasets, custom evaluators, bring your own judge)
- Fiddler AI: Control Plane (policy enforcement, audit trails, framework FAQ)
- Fiddler AI: AI Governance, Risk Management and Compliance
- Fiddler AI: Security (SOC 2 Type II, HIPAA)
- Fiddler docs: Agentic observability (OpenTelemetry traces, supported frameworks)
- Fiddler docs: Agentic AI and LLM framework integrations
- Fiddler AI: Newsroom (2025-2026 coverage and analyst reports)
- Help Net Security: Fiddler Auditor open-source LLM robustness tool (June 2023)
- PyPI: fiddler-auditor (latest release 0.0.5, November 8, 2023; Elastic License 2.0)
- G2: Fiddler AI reviews
- Capterra: Fiddler reviews
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