Current documented limits
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| default API rateRateLimit headers expose limit, remaining, and reset state. | 5 requests per second per team | Default | ResendAug 22, 2026 |
| free sending quotaThe daily and monthly quotas are independent and the first exhausted limit applies. | 100 emails/day and 3,000/month | Free | ResendAug 22, 2026 |
| batch and free contactsBatch requests do not support attachments. | 100 emails per batch; 1,000 marketing contacts on Free | Free and API batch | ResendAug 22, 2026 |
| post-encoding message sizeThe limit applies after base64 encoding, so source binary files need headroom. | 40 MB | Single email | ResendAug 22, 2026 |
How to apply Resend limits safely
The monitored baseline covers default API rate, free sending quota, batch and free contacts, post-encoding message size. Treat these as separate constraints rather than one platform-wide capacity number: a workload can fit one row and still fail another because the plan, model, endpoint, runtime, region, invocation mode, or account scope differs.
- Match the production workload to the exact scope printed beside each value and confirm it in the active Resend console, configuration, or response headers.
- Measure the serialized request, token volume, duration, concurrency, storage, or connection demand at realistic percentiles, then preserve headroom for bursts and retries.
- Check every adjacent layer—client, SDK, gateway, proxy, queue, database, and downstream service—for a smaller effective limit before changing architecture.
Specific limit pages
These pages exist because the constraint has a distinct implementation or troubleshooting intent. Closely related keyword variations stay consolidated.
Resend API Rate Limit
Resend API Rate Limit, verified against Resend's official documentation with scope, implementation impact, caveats, and a direct check.
Resend Free Email Sending Limits
Resend Free Email Sending Limits, verified against Resend's official documentation with scope, implementation impact, caveats, and a direct check.
Resend Batch & Contact Limits
Resend Batch & Contact Limits, verified against Resend's official documentation with scope, implementation impact, caveats, and a direct check.
Resend Email Attachment Size Limit
Resend Email Attachment Size Limit, verified against Resend's official documentation with scope, implementation impact, caveats, and a direct check.