Simulators & Previews

Sinkbox includes rich interactive simulators for each channel to inspect, test, and troubleshoot messages in realistic client environments.

Select a simulator below to learn how each channel preview operates, which rendering quirks are simulated, and how to debug integration payloads:

Email HTML Linter & Simulator

Inspect HTML email compatibility, detect non-inlined CSS and unsupported grid/flexbox, simulate Outlook Windows Word engine rendering, and test dark mode color inversions.

SMS & OTP Simulator

Simulate smartphone messaging with automatic 2FA/OTP code detection, one-click copy, and GSM-7 vs Unicode character segment and multipart count calculations.

Push Notification Simulator

Preview iOS and Android lock screen banners, inspect rich media images, test custom action buttons and deep links, and browse custom JSON payload data.

Voice & IVR Simulator

Simulate incoming voice calls with browser speech synthesis, audio tones, an interactive DTMF keypad, and automated TwiML / voice XML execution flow parsing.

Chat App Simulator

Preview conversational messages formatted faithfully for WhatsApp, Slack, Microsoft Teams, and Discord with channel-specific layout constraints.

HTTP Dump & API Inspector

Inspect generic HTTP payloads and webhooks with searchable interactive JSON trees, decoded JWTs, HTTP headers, query parameters, and cURL export.