Brandwave

Langfuse vs Weights & Biases:Which is more popular?

In September 2026, Langfuse had more branded searches than Weights & Biases among AI evaluation platforms worldwide. Langfuse had about 110,000 branded searches, while Weights & Biases had 51,300. Langfuse made up 39.8% of all AI evaluation platform searches we track, and Weights & Biases accounted for 18.6%. When we asked ChatGPT and Google AI Overviews about AI evaluation platforms, Langfuse appeared in three of the five answers and Weights & Biases in two. Langfuse was mentioned before Weights & Biases in every answer that named either.

Among AI evaluation platforms worldwide in September 2026

Who do people search for more?

Langfuse, about 2 searches for every 1 for Weights & Biases

Langfuse 110K searchesWeights & Biases 51.3K searches

Who does AI mention more?

Langfuse, mentioned in 3 of 5 answers, Weights & Biases in 2

Langfuse in 3 of 5Weights & Biases in 2 of 5

Who does AI recommend more?

Langfuse, named ahead of Weights & Biases in 3 of 3 answers

Langfuse first in 3Weights & Biases never first

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Top AI evaluation platforms in ChatGPT and Google AI Overviews

In three ChatGPT questions and two Google AI Overviews, Langfuse was mentioned in three out of five: in all three ChatGPT answers, but not in either of the two Google AI Overviews. Weights & Biases was mentioned in two out of five: in two of the three ChatGPT answers, but not in either of the two Google AI Overviews. Langfuse was listed before Weights & Biases in every answer that named either.

Most recommended by AI

Brands get a higher ranking if they are mentioned earlier in the answers.

  1. Braintrust1st
  2. LangSmith2nd
  3. Langfuse3rd
  4. Arize4th
  5. Weights & Biases5th
  6. Promptfoo6th
  7. Patronus AI–

Mentioned by AI

Each dot is one answer, filled in when that answer mentions the brand.

  • Arize4 of 5Named in 3 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Braintrust4 of 5Named in 3 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Langfuse3 of 5Named in 3 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • LangSmith3 of 5Named in 3 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • Weights & Biases2 of 5Named in 2 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • Promptfoo2 of 5Named in 1 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Patronus AI0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers

See every answer about AI evaluation platforms

5 answers

Not named in any answer:

Brands are shown in the order each answer named them. The survey took place in the United States on October 20, 2026.

Is Langfuse or Weights & Biases more popular in search?

This chart shows how often people search Google for Langfuse and Weights & Biases by name. Each line represents a brand's share of searches for all seven AI evaluation platforms we track, month by month, from English-language searches worldwide.

Langfuse and Weights & Biases among AI evaluation platforms worldwide, by month

Share of searches by month for Langfuse, Weights & Biases. The figures are in the table below the chart.

View monthly share of searches table
MonthLangfuseLangSmithWeights & BiasesPromptfooArizePatronus AIBraintrust
Oct 202529.5%29.5%31.8%4%4%0.65%0.64%
Nov 202529.5%29.5%31.8%4.8%3.2%0.53%0.64%
Dec 202529.6%29.6%30.5%4.8%4%0.65%0.76%
Jan 202633.5%27.4%28.2%5.5%3.7%0.6%1.1%
Feb 202635%28.6%25.2%5.7%3.8%0.74%0.93%
Mar 202629.9%24.6%21.6%20.1%2.7%0.66%0.52%
Apr 202632.8%27%27.8%8.1%3%0.72%0.72%
May 202634.8%28.7%24.1%7%3.8%0.77%0.76%
Jun 202636.2%29.8%21.4%7.3%3.3%1.2%0.79%
Jul 202637.7%31%18.3%7.6%3.4%1.2%0.82%
Aug 202639.5%26.6%18.3%8%5.3%1.3%1%
Sep 202639.8%26.8%18.6%8%4.4%1.3%1.1%

How has the Langfuse and Weights & Biases comparison changed over the last 12 months?

3 findings
  • The lead changed hands once in the 12 months ending September 2026: Langfuse took it in January 2026.
  • Across the 12 months ending September 2026, Langfuse’s share of searches among AI evaluation platforms worldwide moved from 29.5% to 39.8%, and its estimated monthly branded searches moved from 74K to 110K.
  • Across the 12 months ending September 2026, Weights & Biases’ share of searches among AI evaluation platforms worldwide moved from 31.8% to 18.6%, and its estimated monthly branded searches moved from 79.6K to 51.3K.

How did search popularity change for AI evaluation platforms worldwide in September 2026?

2 changes

  1. Langfuse’s share of searches among AI evaluation platforms worldwide has gained ground for 3 months in a row, from 36.2% to 39.8% in September 2026.

  2. Estimated monthly branded searches for Weights & Biases worldwide fell 35.6% over 12 measured months, from 79.6K to 51.3K in September 2026.

How are branded searches counted?

4 search terms

Brandwave collects information about searches that people make online using Langfuse’s and Weights & Biases’ names. When viewed over time, estimated search volumes for these branded terms can be used to understand whether interest in the brands is growing, holding steady, or fading.

Langfuse

1 branded search term

  • langfuse

Weights & Biases

3 branded search terms

  • wandb
  • weights and biases
  • weights biases

How the Brand Demand Index is measured

Other head-to-heads among AI evaluation platforms

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