The playground

Try any of 1462 endpoints — live.

Pick an endpoint, load a working example, tweak the params, and send — no signup to try. Results render the way the data deserves; raw JSON, headers & code are one tab away.

Playground demo key · api.reefapi.com

post/email-preflight/v1/audit_html2 credits

Full pre-send structure + accessibility + deliverability lint of an HTML email: missing alt text, broken structure, mobile-width risks, dark-mode hints, tracking pixels, external assets, List-Unsubscribe check, Gmail-clip size budget, and prioritized recommendations. Pure local compute (no network).

Working example

Parameters

htmlrequired

text_partoptional

base_urloptional

subjectoptional

check_linksoptional

request preview

curl -X POST https://api.reefapi.com/email-preflight/v1/audit_html \
  -H "x-api-key: $REEF_KEY" \
  -H "content-type: application/json" \
  -d '{"html":"<html><body><img src='https://x.test/a.png'><a href='https://x.test'>hi</a></body></html>"}'

Hit Send to run this endpoint live.