# LangWatch vs PromptLayer

LangWatch records 52,098 monthly visits with +73% month-over-month growth and Contact for Pricing pricing. PromptLayer records 85,899 monthly visits with -4.6% growth and Free Trial, Contact for Pricing pricing.

| Metric | [LangWatch](https://openaitools.app/tool/langwatch) | [PromptLayer](https://openaitools.app/tool/promptlayer) |
| :--- | :--- | :--- |
| Website URL | https://www.langwatch.ai | https://promptlayer.com |
| Categories | Large Language Models (LLMs), AI Monitor, AI Agent, AI Testing | Prompt Engineering, Large Language Models (LLMs), AI Monitor, AI Developer Tools |
| Pricing Model | Contact for Pricing | Free Trial, Contact for Pricing |
| Monthly Visits | 52,098 | 85,899 |
| MoM Growth Rate | +73% | -4.6% |
| Primary Market | United States | United States |
| Direct Visits | 28,986 | 14,092 |
| Review Score | 4.6 | 4.5 |
| Saved Count | 0 | 3 |
| Supported Platforms | Website | Website |

## LangWatch

LangWatch started as an open-source LLM observability tool and has grown into an end-to-end platform for AI platform teams. The tracing layer is OpenTelemetry-native, so agents built with LangChain, LangGraph, CrewAI, Mastra, Pydantic AI or the Vercel AI SDK send spans without a rewrite. Traces carry tokens, cost and cache data, can be explored as waterfalls, flame graphs, topology or sequence diagrams, and are searchable through saved views, plain-language search and automatic topic clustering.

On top of tracing, LangWatch layers evaluation and testing. Teams can score a single output or a whole conversation with an LLM judge, custom code or a full workflow; run evals from a notebook or the shared UI; and evaluate live production traffic. Agentic testing simulates realistic text and voice users that push the agent turn by turn, while red-teaming runs adversarial simulations to surface jailbreaks, policy breaks and unsafe tool calls before users do.

More recent additions target day-to-day operations: an AI Gateway routes every provider call (OpenAI, Anthropic, Google, Bedrock, Mistral) through one endpoint with per-person, per-team and per-customer budgets and minimal overhead; coding agents such as Claude Code and Codex can be brought onto the same observability standard with a single command; and Langy turns a product manager's plain-language goal into a scenario test plan and then into pull requests. LangWatch offers cloud, self-hosted and hybrid deployments and states ISO 27001 certification, GDPR compliance and EU data residency options.

**Pricing & Plans:** LangWatch publishes a dedicated pricing page alongside a book-a-demo path, with plans that scale from individual and team use to enterprise. Self-hosting is available as an option, and the project has open-source roots, but specific tier prices, seat limits and credit allowances should be confirmed on the vendor's current pricing page.

- **OpenTelemetry-native tracing:** Full GenAI spec support means traces from LangChain, LangGraph, CrewAI, Mastra, Pydantic AI, the Vercel AI SDK and any OTel-compatible stack land in the same view, with tokens, cost and cache accounted per span.
- **Offline and online evaluations:** Score single outputs or entire conversations with an LLM judge, custom code or a workflow, run evals from a notebook or UI, and evaluate live production traffic in real time.
- **Agentic testing and simulations:** Simulated text and voice users push agents turn after turn in realistic scenarios, runnable locally and in CI, with tools, skills and MCP servers traced and mockable.
- **AI Gateway and budgets:** Route OpenAI, Anthropic, Google, Bedrock, Mistral and other providers through one endpoint using your own keys, with budgets per person, team and customer and around 11 microseconds of overhead.
- **Red-teaming and prompt management:** Adversarial simulations probe for jailbreaks and unsafe tool calls, while prompts are versioned, deployed and A/B tested as code with full history and GitHub sync.

**Strengths:** OpenTelemetry-native with broad framework support, so adoption usually requires no rewrite; Combines tracing, evals, agentic testing, gateway and red-teaming rather than covering only one layer; Self-hosted, hybrid and cloud deployment options plus ISO 27001 and GDPR statements for security reviews; Open-source roots and an active community make the tracing layer approachable for individual developers

**Limitations:** The expanding surface area (gateway, Langy, coding-agent tracking) means more to configure and learn; Enterprise-grade governance features require a sales conversation rather than self-serve signup; Value depends on instrumenting your stack; teams without tracing in place will need setup work

[Profile (Markdown)](https://openaitools.app/tool/langwatch.md)

## PromptLayer

PromptLayer targets the gap between prototyping with an LLM API and running that application reliably in production. It packages the tooling teams usually end up building themselves: a prompt registry, a visual CMS for editing and versioning prompts, an evaluation harness, and an observability stack that ties production traffic back to the prompt versions that generated it.

The core insight is that prompt quality is a product concern, not only an engineering one. Because prompts live in a dashboard rather than scattered through a codebase, domain experts — product managers, marketers, curriculum designers, support leads — can edit and test them directly, while engineers keep control over what actually ships. Version history, diffs, comments and rollbacks keep that collaboration auditable.

Evidence comes from evaluation and production. Teams define datasets, run automated and human grading, set up regression tests that fire whenever a prompt changes, and backtest new versions against historical data. In production, traces connect each request to its prompt version, so quality, cost and latency can be compared side by side. Agent workflows get the same treatment: prompts, tool calls, evaluations and logs stay in one place for multi-step runs.

**Pricing & Plans:** PromptLayer has a free tier and three paid tiers. Free is $0/month with 5 users, 2.5k requests per month, 1 workspace, 250 eval cell executions and 10MB datasets. Pro is $49/month and adds unlimited playgrounds, unlimited workspaces and 150MB datasets. Team is $500/month with 25 users, 100k+ requests, 7.5k+ eval cell executions and 1GB datasets. Enterprise offers custom limits plus RBAC, deployment approvals, HIPAA with BAA, self-hosted or EU hosting and dedicated support. Overage is billed per transaction (about $0.003 on Pro, $0.002 on Team).

- **No-code visual prompt CMS:** Edit, version, diff and roll back prompts from a visual dashboard with no coding, so product, marketing and content teams can iterate on prompts while engineers keep control of the deploy.
- **Evaluations and regression testing:** Run dataset-backed tests with human and AI graders, trigger regression evals whenever a prompt changes, backtest new versions against historical data and compare prompts across models.
- **Observability and tracing:** Connect production traces to the exact prompt version that produced them and inspect failures, cost, latency and token usage by feature, model or user.
- **Agent workflow support:** Build, trace and improve agent workflows with prompts, tool calls, evaluations and logs in one place, so multi-step runs can be tested before they ship.
- **A/B testing and usage analytics:** Release new prompt versions gradually, compare live metrics, and see exactly how the LLM application is being used, by whom and how often, without jumping to a separate analytics tool.

**Limitations:** Team plan jumps to $500/month, which is steep for small teams that outgrow Pro; Usage beyond plan limits is billed per transaction, so heavy LLM traffic needs forecasting; Role-based access controls, deployment approvals and SSO are Enterprise-only; Live in the developer ecosystem, so setup expects an LLM API and engineering involvement

[Profile (Markdown)](https://openaitools.app/tool/promptlayer.md)

## Frequently Asked Questions

### How do LangWatch and PromptLayer compare in monthly traffic?

LangWatch has 52,098 monthly visits, while PromptLayer has 85,899. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

LangWatch has a month-over-month growth rate of +73%; PromptLayer has -4.6%.

### How does pricing compare?

LangWatch: Contact for Pricing. LangWatch publishes a dedicated pricing page alongside a book-a-demo path, with plans that scale from individual and team use to enterprise. Self-hosting is available as an option, and the project has open-source roots, but specific tier prices, seat limits and credit allowances should be confirmed on the vendor's current pricing page. PromptLayer: Free Trial, Contact for Pricing. PromptLayer has a free tier and three paid tiers. Free is $0/month with 5 users, 2.5k requests per month, 1 workspace, 250 eval cell executions and 10MB datasets. Pro is $49/month and adds unlimited playgrounds, unlimited workspaces and 150MB datasets. Team is $500/month with 25 users, 100k+ requests, 7.5k+ eval cell executions and 1GB datasets. Enterprise offers custom limits plus RBAC, deployment approvals, HIPAA with BAA, self-hosted or EU hosting and dedicated support. Overage is billed per transaction (about $0.003 on Pro, $0.002 on Team).

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [Dify](https://openaitools.app/tool/dify-ai) | 819,691 | -15% | Freemium | Build, deploy, and govern production-ready agentic AI workflows | [.md](https://openaitools.app/tool/dify-ai.md) |
| 2 | [Weights & Biases (CoreWeave Forge)](https://openaitools.app/tool/prompts) | 315,624 | -80.2% | Freemium, Contact for Pricing, Free | Track, evaluate, and ship AI models and agents in one connected environment. | [.md](https://openaitools.app/tool/prompts.md) |
| 3 | [Arize AI](https://openaitools.app/tool/arize-com) | 249,028 | +3.2% | Paid, Contact for Pricing | Agent observability, evaluation, and continuous improvement for production AI | [.md](https://openaitools.app/tool/arize-com.md) |
| 4 | [Portkey](https://openaitools.app/tool/portkey-ai) | 195,650 | -9.4% | Freemium, Paid, Contact for Pricing | AI gateway, observability and guardrails for production LLM apps | [.md](https://openaitools.app/tool/portkey-ai.md) |
| 5 | [Future AGI](https://openaitools.app/tool/future-agi) | 121,741 | -7.8% | Freemium, Usage-based | Build, simulate, evaluate and monitor self-improving AI agents | [.md](https://openaitools.app/tool/future-agi.md) |
| 6 | [Maxim AI](https://openaitools.app/tool/maxim-ai) | 121,351 | +10% | Contact for Pricing, Free Open Source | Evaluate, monitor, and govern your AI applications in production | [.md](https://openaitools.app/tool/maxim-ai.md) |
| 7 | [Respan](https://openaitools.app/tool/respan) | 91,503 | -14.5% | Freemium | Open-source AI gateway with observability and evals built in | [.md](https://openaitools.app/tool/respan.md) |
| 8 | [Confident AI](https://openaitools.app/tool/confident-ai) | 83,400 | -3.3% | Freemium, Paid, Contact for Pricing | Standardize LLM evaluation, observability, and red teaming across your whole org | [.md](https://openaitools.app/tool/confident-ai.md) |
| 9 | [HumanLayer](https://openaitools.app/tool/humanlayer) | 63,865 | -33.4% | Freemium | A multiplayer control plane for AI coding agents | [.md](https://openaitools.app/tool/humanlayer.md) |
| 10 | [Helicone](https://openaitools.app/tool/helicone-ai) | 57,187 | -25.2% | Freemium, Free Trial, Paid, Contact for Pricing, Free | Open-source LLM observability and AI gateway for shipping reliable AI apps | [.md](https://openaitools.app/tool/helicone-ai.md) |

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Source: https://openaitools.app/compare/langwatch-vs-promptlayer

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