SendGrid API Key Tester
Test any AI or API key in your browser — instantly see if it's valid, and why it isn't. Nothing is stored.
Test your SendGrid API key with the mail send endpoint
Data verified 2026-07-13
Key format & how to get one
Prefix: SG. Example: SG.abc.def SendGrid keys start with SG. and contain two dot-separated segments. 1. Visit https://app.sendgrid.com/ and sign up/login 2. Go to Settings > API Keys 3. Click 'Create API Key' 4. Choose 'Restricted Access' and select 'Mail Send' permissions 5. Copy the generated key (it won't be shown again) 6. Free tier: 100 emails/day
How to test
- Copy your key from app.sendgrid.com (Settings > API Keys).
- Paste it into the cURL command above and run it in your terminal.
- A 202 response means the key works; an error explains what's wrong.
Common errors
| Cause | Fix |
|---|---|
| Invalid or revoked key. | Recreate the key at app.sendgrid.com with Mail Send access. |
| The key lacks Mail Send permission, or the sender isn't verified. | Give the key Mail Send scope and verify your sender identity. |
Cannot test this key from your browser
This provider blocks in-browser requests or requires a server-side secret. Test it from a terminal instead:
curl -sS -X POST https://api.sendgrid.com/v3/mail/send -H 'Authorization: Bearer {{KEY}}' -H 'Content-Type: application/json' -d '{"personalizations":[{"to":[{"email":"test@example.com"}]}],"from":{"email":"test@example.com"},"subject":"Test Email","content":[{"type":"text/plain","value":"Hello world!"}]}'Related tools
Building with AI APIs? Elegant Atomics turns AI capability into B2B SaaS growth. Work with us →