
Helicone AI
LangSmith
LangChain
Portkey
Braintrust.dev
PromptLayer
liteLLM
Langfuse is an open-source LLM engineering platform that helps teams collaboratively debug, analyze, and iterate on their LLM applications.
JSON Placeholder
JSON Server
mocki Fake JSON API
httpbin(1)
MockRest
Nacapi
Format JSON Online
A hosted REST-API ready to respond to your AJAX requests.

Which is more popular?
Based on our record, Langfuse should be more popular than ReqRes. It has been mentioned 36 times since March 2021.
Website, pricing, platforms and company facts side by side.
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ReqRes
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| Website | langfuse.com | reqres.in |
| Pricing | — | |
| Company | Startup from the United States | — |
| Listed in |
In their own words, as submitted to SaaSHub.

Langfuse is an open-source LLM engineering platform designed to empower developers by providing insights into user interactions with their LLM applications. We offer tools that help developers understand usage patterns, diagnose issues, and improve application performance based on real user data....
No description of ReqRes yet.
What each product offers, as listed by its team.

Possible disadvantages
Possible disadvantages
Walkthroughs and reviews on video.
Langfuse in two minutes
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How often each product is chosen within a category, 0–100% relative to the other.

Share your experience with using Langfuse and ReqRes. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.

Ten free AI prompt tools in 2026 across four categories: prompt generators (SurePrompts, Anthropic Console, OpenAI Playground), libraries (AIPRM, PromptHero, FlowGPT, Awesome ChatGPT Prompts), open-source workflow...
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Recommendations tracked on public social media and blogs since March 2021.

Your agent gave a wrong answer, and every span in the trace is green. Both TraceRoot and Langfuse will show you that trace. This post compares what each one does next, from tracing and detection to a root cause and a fix. - Source: dev.to / 3 days ago
Langfuse is an open-source LLM engineering platform specialized for AI applications. It provides:. - Source: dev.to / about 1 month ago
Langfuse is an open-source observability and analytics platform for LLM applications. Its open-source nature is a significant draw for companies that prefer to self-host or want to avoid vendor lock-in. - Source: dev.to / about 1 month ago
Https://reqres.in/ - roughly that much in ads revenue. Would love to add a paid plan for more features, but....time. - Source: Hacker News / almost 2 years ago
Reqres.in - A Free hosted REST-API ready to respond to your AJAX requests. - Source: dev.to / over 2 years ago
As stated earlier we are using the REQ | RES API in the example, you can check it out to see all the methods it provides. Now, go to the core/internet_services/ create a dart file and name it paths.dart, this will contain the baseurl and... - Source: dev.to / over 3 years ago
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