Subtrace alternatives
6 products compared · Updated November 12, 2026
The short answer
The three strongest alternatives to Subtrace depend on what you need to see. Langfuse suits engineering teams building LLM or agent products who want traces, evals and cost tracking for AI calls. Helicone suits AI product teams that want to monitor and route LLM provider calls with usage-based pricing. LangChain suits teams building LLM agents that need step-by-step tracing, evals and production monitoring of agent runs. None of these three traces general HTTP traffic across a whole backend the way Subtrace does.
Your shortlist, at a glance
Read the comparisons ↓
LangfuseNot publishedEngineering teams building LLM or agent products who need traces, evals and cost tracking for AI calls- HHeliconeNot publishedAI product teams that want to monitor and route LLM provider calls with usage-based pricing and open-source tooling
- LLangChainFrom $0 (5k traces/mo)Teams building LLM agents that need step-by-step tracing, evals and production monitoring of agent runs
- AArize AIFrom $0 (free tier)AI product teams shipping chatbots, RAG systems or agents who need to measure output quality and trace LLM calls
BraintrustCustom quoteEnterprise hiring teams that need vetted contractors or AI-assisted candidate screening at volume- WWeights & BiasesNot publishedAI and ML teams that need experiment tracking, training run comparisons and LLM application tracing in one system of record.
About Subtrace and its alternatives
Subtrace is a network monitoring tool that shows every HTTP request in a production infrastructure without code changes. According to its site, it is known for one-command setup, full request payloads, latency breakdowns, and replaying production requests locally.
When comparing alternatives in this category, look at what each tool actually traces. Some focus on AI model calls, others on hiring or ML experiments, and only general request tracers cover backend HTTP traffic. Also weigh pricing structure, since some vendors publish plan figures while others require a sales conversation, along with supported languages and integrations, support options, and contract terms such as self-hosting and data retention.
Explore the alternatives
- Not published
1.Langfuse
Best for: Engineering teams building LLM or agent products who need traces, evals and cost tracking for AI calls
- Pricing
- Not published
- Category
- AI & Machine Learning
Langfuse is an open source platform for tracing, evaluating and managing prompts for LLM and agent applications. Teams pick it over Subtrace when they need visibility into AI calls specifically, such as token spend, prompt versions, evals and human review, rather than general HTTP request monitoring across the whole infrastructure.
Where it is strong
- MIT licensed and self-hostable, so you keep control of your data
- Covers prompt management, evals, datasets and human annotation alongside tracing
- Works with OpenTelemetry and has a free tier with 50k units per month
Where it falls short
- Focused on AI calls, so it does not show general HTTP traffic across your infrastructure the way Subtrace does
- Free tier history is limited to 30 days and rate limits are lower
- Pricing:
- Pricing is not published on the site.
- HNot published
2.Helicone
Best for: AI product teams that want to monitor and route LLM provider calls with usage-based pricing and open-source tooling
- Pricing
- Not published
- Category
- AI & Machine Learning
Helicone is an observability layer and gateway for LLM applications. It logs prompts, tokens, costs and latency for AI calls, and it can route requests, cache responses and fall back to other providers when one fails. Someone would pick it over Subtrace when their main concern is AI provider traffic rather than general HTTP traffic across their whole backend.
Where it is strong
- Built specifically for LLM calls, with caching, rate limits and automatic fallbacks
- Works with many LLM providers and is open source
- Offers a free tier, a 7-day trial on paid plans, and discounts for startups under two years old
Where it falls short
- Focused on AI requests, so it does not trace all of your general backend HTTP traffic the way Subtrace does
- The site says Helicone is now part of Experiential Labs, with details to come, so its future direction is uncertain
- Pricing:
- Pricing is not published on the site.
- LFrom $0 (5k traces/mo)
3.LangChain
Best for: Teams building LLM agents that need step-by-step tracing, evals and production monitoring of agent runs
- Pricing
- From $0 (5k traces/mo)
- Category
- AI & Machine Learning
LangChain is an AI agent platform. It offers open source frameworks for building agents, plus LangSmith for tracing, evaluating, deploying and monitoring them. Choose it over Subtrace when your problem is the behavior of LLM agents and their steps, not raw HTTP traffic across your infrastructure.
Where it is strong
- Step-by-step tracing and evals built for LLM agent runs
- Open source frameworks with a choice of model provider
- Self-hosted, hybrid and SaaS deployment options
Where it falls short
- Focused on AI agents, so it does not give general request-level visibility across your infrastructure the way Subtrace does
- Enterprise features such as self-hosting and custom SSO sit behind sales contact
- Pricing:
- The Developer plan includes 5k base traces per month and 1 seat, and the Plus plan includes 10k base traces per month with unlimited seats, with pay-as-you-go beyond those limits and custom Enterprise pricing.
- AFrom $0 (free tier)
4.Arize AI
Best for: AI product teams shipping chatbots, RAG systems or agents who need to measure output quality and trace LLM calls
- Pricing
- From $0 (free tier)
- Category
- Other
Arize AI is an observability and evaluation platform for AI agents and LLM applications. It traces what an agent did on each request, scores output quality with evals, and tests prompt or model changes before they reach production. Someone would pick it over Subtrace when the problem is quality of model outputs, not raw HTTP traffic.
Where it is strong
- Traces every LLM call and agent step with OpenInference, built on OpenTelemetry.
- Runs evaluations on spans, traces and sessions, including online evals on production traffic.
- Phoenix is open source and can run locally or self-hosted.
Where it falls short
- It focuses on AI workloads, so it does not give you the zero-code, full-payload HTTP view across all your backend services that Subtrace doe
- Free tier retention is 15 days and the span and ingestion caps are small for busy production apps.
- Pricing:
- The free AX plan includes 25k trace spans and 1 GB of ingestion per month, the AX Pro plan is $50 per month with 50k spans and 10 GB, and Enterprise pricing is custom.
- Switching from Subtrace:
- Moving from Subtrace would mean instrumenting your LLM calls with OpenInference or OpenTelemetry, since Subtrace's no-code network capture does not carry over.
- Custom quote
5.Braintrust
Best for: Enterprise hiring teams that need vetted contractors or AI-assisted candidate screening at volume
- Pricing
- Custom quote
- Category
- Other
Braintrust is a talent network with three products: a Talent Marketplace of vetted professionals, AIR, an AI recruiter that runs screening interviews, and Nexus, which builds AI agents for operational work like revenue ops and onboarding. Someone would pick it over Subtrace if they need to hire people or automate business processes, not debug network traffic in production.
Where it is strong
- Access to a talent pool of 2M+ vetted professionals across engineering, design, product, and operations
- AIR runs conversational voice interviews with role-specific scoring, and humans make the advance decisions
- Nexus automates manual operational work across tools that have an API, with no developer needed to set it up
Where it falls short
- Pricing for AIR and Nexus is not published as fixed numbers, so budgeting requires a sales conversation
- It does not offer any network tracing, request inspection, or latency debugging, so it does not replace Subtrace for engineering observabili
- Pricing:
- AIR is priced on interview volume with no public per-interview price, Talent Marketplace has flexible pricing with zero platform fees for talent, and Nexus takes 25% of measured savings.
- WNot published
6.Weights & Biases
Best for: AI and ML teams that need experiment tracking, training run comparisons and LLM application tracing in one system of record.
- Pricing
- Not published
- Category
- Other
Weights & Biases is built for tracking machine learning experiments, training runs and, through its Weave product, GenAI application traces. Choose it over Subtrace when your main job is comparing model training runs and evaluating AI outputs, not watching live HTTP traffic across production services.
Where it is strong
- Built for ML experiment tracking and model training workflows
- Compliance certifications include ISO 27001, SOC 2 and HIPAA
- A mobile app lets you monitor training runs from anywhere
Where it falls short
- It does not offer the zero-code HTTP request tracing and request replay that Subtrace focuses on
- Its product is now part of CoreWeave Forge, so the offering is changing
- Pricing:
- Pricing is not published on the site, though the page says academic research is free and points to CoreWeave Forge pricing for details.
See more comparisons in Developer Tools alternatives.
FAQ
Questions about Subtrace alternatives
Which alternative is closest to Subtrace for general HTTP tracing?
None of the alternatives listed here traces general HTTP traffic across a whole backend the way Subtrace does. Each of them focuses on AI calls, agents, ML experiments or hiring. If you need request-level visibility across all your services, Subtrace is the tool these entries are compared against rather than replaced by.
Which alternative should a team building an LLM app consider first?
Langfuse is an open source option for tracing, evaluating and managing prompts for LLM and agent applications, and it is self-hostable under an MIT license. Helicone is a good choice if you also want caching, rate limits and automatic provider fallbacks. Both focus on AI calls rather than all of your backend traffic.
Are there self-hosted or open source options?
Yes. Langfuse is MIT licensed and self-hostable, and Arize AI's Phoenix is open source and can run locally or self-hosted. LangChain also offers self-hosted deployment on its Enterprise tier, with custom pricing. Subtrace itself describes its product as always open source.
How do the pricing models compare?
LangChain publishes plan figures, with a Developer plan including 5k base traces per month and a Plus plan including 10k with unlimited seats. Arize AI's free AX plan includes 25k trace spans per month, and its AX Pro plan is $50 per month. Langfuse, Helicone, Braintrust and Weights & Biases do not publish full pricing on their sites, so expect to ask sales for quotes.
Can any of these tools replace Subtrace for debugging production latency?
Not directly. Arize AI, Langfuse and LangChain trace AI calls and agent steps, which can show where model latency comes from, but they do not inspect every HTTP request across your infrastructure. Braintrust and Weights & Biases do not offer request tracing at all. Teams that need zero-code request inspection and replay will still need a general network tracer such as Subtrace.
Last updated November 12, 2026.