Key findings
- All 11 sources that discuss integrations are positive, and all but one of the 15 that discuss trace-level debugging praise it.
- 26 of the 30 sources that say where they run Langfuse self-host it, and 14 raise the cost of running ClickHouse and the services around it.
- Datasets and evaluations work for Ramp and one developer's CI pipeline. Five developers hit evaluators that never ran, judge scores that would not filter, experiments that broke on Anthropic thinking blocks, and agent traces that were hard to turn into dataset items.
- Amplifon's engineers describe deploying Langfuse as a shared platform for its AmplifAI program, with tracing and evaluations built into agent blueprints. SuperDial self-hosts it for healthcare calls, and Khan Academy gives Khanmigo features tracing through a common Go interface. Merck's 80+ project teams and DKB remain vendor customer stories outside the public-account counts.
Langfuse wins teams on open source, self-hosting and integrations, and loses them on the work of running ClickHouse. Of 21 public accounts that describe a platform choice, 11 chose or kept Langfuse and 10 picked another tool, most often to run less infrastructure. GILD read the public accounts that teams and developers published between February 2025 and October 2026.
What teams get from it
The teams with the most detailed accounts use Langfuse to feed production failures back into testing. Ramp's Reflect agent scores and clusters traces and proposes fixes for an owner to accept. On its Research agent alone, Ramp reports 10 to 20% fewer tokens and 30% faster sessions. Cresta walks the trace tree to find the step where an agent chain went wrong.
Prompt management divides users. A recruiting-agent team stored model, provider and temperature settings in the prompt config so it could switch models without a deploy, and NonBioS chose Langfuse partly for its prompt store. Three of 7 sources found it too basic. They missed conditional sections, and a team that chose PromptLayer missed git-like release labels and rollback.
Why teams choose it
Open source and self-hosting drive most decisions. NonBioS chose it over Helicone for maturity and code it could extend. After three months with Galileo, Arize, and LangSmith, a small team chose Langfuse because it self-hosts in full and accepts OpenTelemetry. Developers on Hacker News and Reddit give the same reasons, plus price and integrations that work without LangChain.
What self-hosting and upgrades cost
Langfuse v3 moved traces to ClickHouse, which made self-hosting heavier, and complaints run through the whole period. A team that ran v2 on developer laptops found ClickHouse spiking CPU while idle. In one developer's MCP server stack, the ClickHouse shard used more memory than headless Chrome. A tuned v4 stack needed four containers and 1,848 MiB, and a laptop instance grew to terabytes.
Several teams cut it. One template dropped Langfuse and its ClickHouse and MinIO containers for hosted LangSmith. Another project replaced six Langfuse containers with a Grafana stack, and two developers moved to a single Phoenix container.
Upgrades are the second cost. Developers describe the v2 to v3 migration as painful, and a ClickHouse migration failed mid-upgrade in 2025. Brainforge's August 2026 move to v4 caused the costliest of the 18 integration problems it logged. Langfuse Cloud's v4 cutover on November 16, 2026 sent Medic, Traigent, and open-source projects such as CAMEL and Sure into SDK and API migrations in September and October 2026.
Why some choose another tool
Teams that leave want less to run or a stronger feature elsewhere. A small startup picked Phoenix as the one tool that worked with OpenTelemetry out of the box. Bayes Impact merged a move of its platform's traces to Phoenix over plain OpenTelemetry. A team picked PromptLayer for its git-like prompt API while rating Langfuse better at tracing, and one developer moved to Sentry. Kyle Rush's team considered Langfuse and chose LangSmith because Rush already knew it.
Teams guard against lock-in with OpenTelemetry. Eleven sources instrument with it so they can change backends. digithings.ai planned to send the same spans to Langfuse and LangSmith before dropping LangSmith, then on October 9, 2026 replaced the Langfuse plan with Cloudflare-native tracing and MLflow.
What to settle before choosing
Answer these questions before you compare feature lists.
- Must traces stay in your own network? If so, who will own ClickHouse, and do you need an Enterprise key for retention and project roles?
- If you use Cloud, how many units does a week of traffic produce once every observation and score counts?
- Which integrations still use SDKs or APIs that stop working on Cloud on November 16, 2026?
- Which failures become dataset items, and who reviews judge scores against human labels?
- Will people outside engineering edit prompts, and what happens when the prompt store is unreachable?
Methodology
GILD reviewed 72 public Langfuse sources, 63 on October 12, 2026, 5 more on October 25, 2026, and 4 engineering talks on October 26, 2026, all published in 2025 or later. They include Hacker News and Reddit posts, GitHub issues and pull requests in langfuse/langfuse and team repositories, and blog posts by companies and individual engineers. The rest are seven talks and a Product Hunt review. GILD searched Hacker News through Algolia and Reddit through Arctic Shift. Every count in this piece counts these 72 sources. GILD excluded Langfuse's blog, customer stories, comparison pages and staff posts. The Merck and DKB customer stories add context and sit outside the counts. The Ramp talk appeared on the YouTube channel of ClickHouse, Langfuse's parent company. GILD checked product behavior against Langfuse's docs on October 12, 2026.
Products in this piece
Sources
- Public source
- 24
- Official documentation
- 6
- Amplifon engineers: One Registry to Rule them All (Apr 10, 2026)
- Shawn Jansepar: Scaling AI in Education (Feb 5, 2025)
- SuperDial: Voice AI (Apr 18, 2025)
- Ramp engineers Ryan and David: How Ramp uses Langfuse, talk on ClickHouse's YouTube channel (Sep 17, 2026)
- James Idzik, Cresta engineering blog: Tracing multi-service LLM pipelines with Langfuse (Mar 26, 2026)
- r/LLMDevs: What I learned using Langfuse in a real AI recruiting agent (Jun 3, 2026)
- r/LLMDevs: Three months evaluating Galileo, Arize, Langfuse, and LangSmith (May 30, 2026)
- digithings issue #4928: self-hosted Langfuse on Cloudflare, cut LangSmith (Oct 1, 2026)
- NonBioS: The NonBioS LLM Observability Pick (Mar 5, 2025)
- langfuse issue #6572: v3 ClickHouse CPU consumption (Apr 23, 2025)
- Hacker News comment: the Langfuse ClickHouse shard uses more memory than headless Chrome (Jan 12, 2026)
- jordimo/infra pull request #15: standardise on Phoenix, keep Langfuse v4 as fallback (Aug 6, 2026)
- Titus Lim, pull request #14: cut local stack from about 47 containers to 14, Langfuse to LangSmith (Sep 3, 2026)
- DraftPilot issue #32: Temporal replaces ARQ, Langfuse removed (Sep 27, 2026)
- langfuse issue #5577: ClickHouse migration failure after v3.28.2 (Feb 16, 2025)
- Uttam Kumaran (Brainforge): How we migrated to Langfuse v4 ahead of the cutover (Sep 18, 2026)
- Medic cht-agent pull request #162: migrate Langfuse to JS SDK v5 (Sep 23, 2026)
- Traigent pull request #2520: read traces via Observations API v2 before the Cloud v4 cutover (Oct 7, 2026)
- CAMEL pull request #4349: migrate the Langfuse integration to the v4 SDK (Sep 21, 2026)
- Hacker News comment on choosing Phoenix at a small startup (Sep 28, 2025)
- bayesimpact/bayes-platform pull request #877: send traces to Phoenix instead of Langfuse (Sep 29, 2026)
- Hacker News comment on choosing PromptLayer for prompt management (Jan 18, 2026)
- Hacker News comment on migrating from Langfuse to Sentry (Jan 17, 2026)
- Kyle Rush on Product Hunt: Review of LangSmith (Jun 22, 2025)
- Langfuse docs: Self-host Langfuse
- Langfuse changelog: Langfuse v4 is live (Aug 17, 2026)
- Langfuse docs: Billable units
- Langfuse docs: Prompt management
- Langfuse customer story: How Merck is serving 80+ AI project teams globally on Langfuse (Sep 2, 2025)
- Langfuse customer story: How DKB uses Langfuse to keep its AI banking assistant accurate, compliant, and trustworthy at scale (Aug 31, 2026)