100% en el navegador y privado

Email Subject Line Length & Preview Checker

Client-Side Sandbox
100% In-Browser Privacy All computations and file processing run strictly in your browser. Zero server data uploads.

Optimize email subject lines for mobile and desktop inboxes (Gmail, Outlook, iPhone) with live previews.

Inbox Visibility & Truncation Tester

Test email subject line lengths against mobile and desktop inbox cut-off thresholds (Gmail, iPhone Mail, Outlook).

Character Count 0
Word Count 0
Mobile Friendly (≤ 41 Chars) -
Desktop Friendly (≤ 60 Chars) -

Simulated Inbox Previews:

iPhone Mail (~38 chars):
Gmail Desktop (~60 chars):
Estándares verificados
Resultados precisos y deterministas Probado según especificaciones oficiales para obtener resultados reproducibles y fiables.

Cómo usar esta herramienta

  1. Type or paste your text directly into the editor workspace above.
  2. Select formatting options, case conversion, or analytical filters.
  3. View real-time statistics or transformed text instantly, then click Copy or Download.

Formatos admitidos, límites y privacidad

Entradas y límites: Browser client-side processing limits apply (e.g. max recommended image size 25MB).

Cero recopilación de datos: Esta herramienta se ejecuta al 100% dentro del motor JavaScript del navegador del cliente. Ninguna pulsación de teclas, valores, archivos o resultados calculados se almacenan o transmiten a ningún servidor remoto.

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