Email Preheader Tester
Paste your subject and the first 200 characters of your email body. The tool shows what the inbox preview will look like in each client and flags the common preheader leak.
⚠️ No explicit preheader — body text is leaking into preview. Add a hidden div at the top of body to control this.
Simulates the preview window for Gmail (~90 chars), Outlook (~55 chars), Apple Mail iOS (~85 chars), Outlook mobile (~60 chars). Flags when no explicit preheader is set and the first body line leaks into preview.
Before sending. The preheader is the second-most-read piece of copy in an email (after the subject); rendering it wrong wastes the attention you paid for.
FAQ
How do I set an explicit preheader?+
Add a hidden div at the very top of the email body: `<div style='display:none;font-size:1px;line-height:1px;'>YOUR PREHEADER</div>` followed by enough zero-width-spaces to push body text past the preview cutoff.
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Articles, glossary entries, and other tools on the same topic.
You analyzed one send. Outsolvi analyzes every send, forever.
Subject scores, preview tests, header parses are one-shot. Outsolvi runs the same analysis on every email you send and surfaces patterns: which subjects open, which preheaders convert, which threads stall. From $7/user/mo yearly.
Get the continuous versionNate built Outsolvi after watching every email-tracking tool he had ever used lie to him about opens. Outsolvi runs Tier 1 to 5 confidence scoring on every open, native in Outlook and Gmail, so the number on the dashboard is one a rep can actually act on.
We update these pages when the underlying mechanics change — new mailbox-provider rules, new tracker behavior, new measurement gaps. The dates above are real revisions, not auto-touches.