Formspree vs LangSmith
Form backend as a service — point your HTML form at a URL and done
vs. LLM observability, testing & evaluation — by LangChain
Pricing tiers
Formspree
Free
$0. 50 submissions/mo. 1 form. Formspree branding in emails. Basic spam filtering.
Free
Basic
$10/mo. 500 submissions/mo. Unlimited forms. Custom success redirect. Honeypot anti-spam.
$10/mo
Professional
$20/mo. 1,000 submissions/mo. reCAPTCHA, webhooks, integrations, rules engine.
$20/mo
Unlimited
$40/mo. 2,500 submissions. File uploads, team members, priority support.
$40/mo
Enterprise
Custom. SSO, SAML, HIPAA, high volume, dedicated support.
Custom
LangSmith
Developer (Free)
Free forever. 5,000 traces/month. 14-day retention. 1 seat. Basic evaluations.
Free
Plus
$39/seat/month. 10k base traces included ($2.50 per 1k overage). Full evaluations, custom dashboards, email support.
$39/mo
Enterprise
Custom. Self-host option, SSO, custom retention, dedicated support.
Custom
Free-tier quotas head-to-head
Comparing free on Formspree vs developer on LangSmith.
| Metric | Formspree | LangSmith |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
Formspree · 11 features
- Custom Success Redirect — Redirect after submit.
- Email Notifications — Submissions delivered to inbox.
- File Uploads — Accept attachments (Unlimited).
- IP Filtering — Block spam IPs.
- React SDK — Hooks + state management.
- Rules Engine — Conditional routing, auto-responders.
- Spam Protection — Honeypot + reCAPTCHA + keyword filter.
- Submission Analytics — Volume + source stats.
- Team Members — Multi-user (Unlimited).
- Webhooks — POST submissions to your server.
- Zero Backend — HTML <form action> → email.
LangSmith · 14 features
- Alerts — Threshold alerts on latency, cost, eval metrics.
- Annotation Queues — Human-review workflows for trace quality rating.
- Custom Dashboards — Aggregate metrics dashboards per project/tag.
- Datasets — Collect examples → use as eval sets or training data.
- Evaluations — LLM-as-judge, embedding similarity, custom Python evaluators, offline batch eval…
- LangChain Integration — Auto-trace any LangChain/LangGraph run with env var.
- LangGraph Integration — First-class trace + eval for LangGraph agents.
- LLM Tracing — Automatic trace every LLM call + tool call + chain step.
- OpenTelemetry Export — Export traces as OTLP to Datadog/Honeycomb/etc.
- Playground — Test prompts + models inline before deploying.
- Prompt Canvas — Visual prompt editor with live test + eval.
- Prompt Hub — Public + private prompt library with versioning.
- Self-Hosted (Enterprise) — Docker + k8s deployment in your infra.
- Threads + Sessions — Group traces into conversational sessions.
Developer interfaces
| Kind | Formspree | LangSmith |
|---|---|---|
| CLI | — | LangSmith CLI |
| SDK | @formspree/core, @formspree/react | langsmith-js, langsmith-python |
| REST | Formspree REST API | LangSmith REST API |
| MCP | — | LangSmith MCP |
| OTHER | Direct HTML Form Submit, Formspree Dashboard, Formspree Webhooks | LangSmith Dashboard |
Staxly is an independent catalog of developer platforms. Some links to Formspree and LangSmith may be affiliate links — Staxly may earn a commission if you sign up through them, at no extra cost to you. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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