Free tools
Free utilities for previewing, testing, and debugging notifications across email, SMS, push, chat, and in-app channels. No signup required.
Realistic mockups of every notification channel, exported as PNGs.
Tracking, mailto, and calendar links, encoded correctly every time.
Check the DNS records that decide whether your email lands.
Yes. Every tool on this page is free, needs no signup, and has no usage cap.
No. The preview generators and link builders run entirely in your browser, and the PNG export is drawn locally. The deliverability checkers are the one exception: the domain you enter goes to a public DNS resolver, Cloudflare first and Google as a fallback, so the tool can read that domain's published records. Those records are public either way.
An iPhone 17 at 393 by 852 points running iOS 26, and a Pixel 10 at 412 by 915. The chrome around your message is rebuilt to match what those platforms render today, so the space your text has to fit into is the real one.
Because the phone is where the constraint bites. A subject line or push title that survives a phone's truncation survives a desktop client too, so the roomier surface is not the one worth designing against.
The DNS lookups your SPF record costs, against the limit of 10 that RFC 7208 sets. Nested includes are followed and counted recursively. If a target cannot be resolved, the result is marked partial rather than reported as a clean total.
No. Nothing here is gated. Courier is the notification API these tools came out of, so you will find links to it, but every tool works without an account.
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