The short version
Same starting point. Different route after submit.
Web3Forms gets an email to you without a service to run, and many sites will never need more. Postbag keeps the messages, sends them where they belong, signs notifications, and can run on your own infrastructure.
The evidence
What each service says it does.
These are not ratings. They are the practical details that tend to matter after a Form is live.
| Capability | Postbag | Web3Forms |
|---|---|---|
| Free tier | 5 forms, 1,000 submissions/month, 5 destinations, 90-day retention | 250 submissions/month, unlimited forms/access keys (Web3Forms pricing) |
| Entry paid | Pro $15/month ($12/month billed yearly); Team $49/month ($39/month billed yearly) | Pro $12/month or $149/year |
| Management API | Your agent can create, inspect and manage forms from one API | Submissions API documented; form management API not verified |
| Webhooks | Yes; HMAC-signed when a secret is configured, with visible retries | Yes on Pro; signing not verified |
| Yes (Resend), Reply-To from the submission | Yes (the core product) | |
| Chat destinations | Telegram today; Slack and Discord next | Slack, Discord, Telegram |
| Spam | Honeypot, rate limits, approved origins and Cloudflare Turnstile; flagged messages stay available to review | hCaptcha free; reCAPTCHA/Turnstile on Pro; honeypot |
| File uploads | Not yet (text fields only; 256 KB) | Pro |
| Self-hosting / source | Yes, the same product you use in the cloud | No (client plugins are open source) |
| Keeping fields tidy | Keeps changing field names clear and catches surprises before they spread | No |
| Many sites, one place | Keep forms from many sites together, then send each one where it belongs | Agency and Team plan |
| For AI agents | Your agent can set up, test and manage a form without a browser | docs llms.txt; no MCP or CLI found |
On a small screen, the table scrolls sideways so the full wording stays readable.
Source note Web3Forms facts checked on against: web3forms.com/pricing, docs.web3forms.com. Prices and quotas change, so check the vendor pages before deciding. Tagline quoted: "Receive form submissions directly in your email inbox without any server or back-end code".
The practical choice
Both can be the right answer.
Choose Web3Forms if
- You want email notifications for a static site and nothing else, for free.
- You need Telegram, Slack and Discord today on the free tier.
Choose Postbag if
- You want every message and sending attempt kept, not only an email.
- You send messages to a CRM or partner and need to know they came from Postbag.
- Self-hosting or agent-run setup matters.
What Postbag keeps hold of
The Submission does not disappear into the notification.
Postbag treats a Submission as a database row before anything else and Delivery as an outbox drained by a worker. Each Delivery keeps its retry count and latest outcome, including for spam. Streams let many Forms with different field names map onto one versioned Schema and reach one partner or CRM with windows and digests. Add a secret and Postbag signs each webhook attempt. The same /openapi.json and /llms.txt describe the API an agent uses to create, verify and route a Form without a browser. And it ships as one Docker image plus Postgres, so the hosted product and a self-hosted install are the same thing.
