Comparison

Fiddler vs OpenLLMetry

A like-for-like, spec-level comparison. Both entries are verified against their docs and repo.

Fiddler

AI observability and governance for enterprise.

+ Strong governance and compliance story
+ Good for regulated enterprise
− Enterprise-priced
− Heavier than dev-focused tools

OpenLLMetry

OpenTelemetry instrumentation for LLMs.

+ Vendor-neutral instrumentation
+ Works with existing observability stacks
− Instrumentation only, no UI
− Needs a backend like SigNoz or Honeycomb

Spec	Fiddler	OpenLLMetry
Category	eval-observability	eval-observability
License	Proprietary	Apache-2.0
Open source	No	Yes
Self-hostable	No	Yes
MCP support	No	No
Pricing	paid	free
Starting price	Custom (enterprise)	Free
Models	multi	multi
Languages	python	python, typescript
GitHub stars	—	7.2k
Last activity	—	2026-06-25