Free tools

Small tools for the fiddly parts of email, SMS and webhooks. They run in your browser, so there's no account and nothing you paste leaves the page.

Tools

SMS segment calculatorPaste a text message and see how many segments it takes, which encoding it needs and which characters force UCS-2. Runs in your browser.
Webhook signature verifierCheck a webhook's signature against its secret and find out why it fails. For Standard Webhooks requests, including coss.com's. Runs in your browser.
DMARC record generator and checkerBuild a DMARC record to publish at _dmarc.yourdomain, or paste one to see what each tag means and what's wrong with it. Runs in your browser.