CheckGmail.online provides online tools for checking Gmail address status and organizing email data. Its Gmail checker processes addresses in bulk and reports results such as live, disabled, verification required, unregistered, or unknown. Users can enter addresses as text or upload a TXT file, then review, copy, or export the results. The free plan supports batches of up to 500 emails at standard speed, with no password required; the site states that email data is processed in browser memory and cleared when the page is refreshed.

The service offers fast and slower checking modes, while a deeper web-only check is described as a members-only feature. VIP plans provide higher-speed checking and, for eligible six-month and one-year subscribers, API access for integrating fast or slow checks with scripts or bots. Additional utilities include email splitting, column splitting, an online notepad, an authenticator tool, and check-history and profile features. The website also provides API documentation and account support through Telegram.