Email Subject Line Character Counter

The ideal email subject line length depends on where most of your subscribers read their email. For desktop Gmail, you have about 70 characters before truncation. Outlook shows roughly 60 characters. Mobile devices typically display only 35-40 characters. The safest approach is to front-load your most important words into the first 40 characters so the core message is visible everywhere, then use the remaining characters for context or secondary details.

Character count treats every letter equally, but email clients render subject lines using proportional fonts where an uppercase W takes up far more horizontal space than a lowercase i. Pixel width gives you a more accurate picture of how much screen space your subject line actually occupies. Our tool estimates pixel width at roughly 7 pixels per character as an average, which is a reasonable approximation for the sans-serif fonts most email clients use. The actual width varies slightly across email clients.

Preheader text is the snippet of text that appears next to or below your subject line in the inbox preview. In Gmail, it shows as grey text after the subject line. In Apple Mail, it appears on a second line. If you do not set a preheader explicitly, email clients will pull the first text from your email body -- which is often "View in browser" or navigation links. Setting a deliberate preheader gives you a second chance to convince someone to open your email. Aim for 40 to 130 characters for optimal display across clients.

Gmail truncates subject lines to fit within the available column width in the inbox view. The exact cutoff depends on the user screen resolution, browser zoom level, and whether the inbox is in default, comfortable, or compact density mode. The commonly cited 70-character limit is an approximation for standard desktop displays. On mobile Gmail, the cutoff drops to about 40 characters. Gmail appends an ellipsis when it truncates, so your subject line ends with "..." if it is too long.

Emojis can increase open rates by making your email stand out in crowded inboxes, but they come with trade-offs. Each emoji typically takes about 12-16 pixels of width -- roughly twice a normal character -- which means they eat into your available space faster than letters. Some email clients render emojis differently or not at all. Outlook on Windows, for example, often shows black-and-white versions. Our character counter counts each emoji as one character but factors in the wider pixel width in the estimated display. Use emojis sparingly and test rendering before sending.