Preview the row
How it works
Enter
Sender name, subject and the first line of the body. The first line is what every client uses as preview text unless a preheader is set.
Render
Each client's row is drawn with its real truncation point: Gmail desktop shares one line, Gmail mobile and iPhone cut the subject near 40 characters, Outlook near 60.
Score
Length, word count, capitals, punctuation, spam phrases, fake RE:, unrendered variables, and the greeting-as-preview trap.
Fix
The notes say which line to change. Re-run until the phone row carries the point.
The row is the whole first impression
Before anyone opens a cold email they see three things: a name, a subject, and whatever the client chose to show as preview text. On a phone — where most first opens happen — the subject is cut at around forty characters and the preview at ninety. A subject that works at seventy characters on a laptop is half a sentence on an iPhone, and the preview text underneath is either the point of the message or "Hi Priya," depending on how the body starts. This tool draws the row the way each client draws it so you can see which you are sending.
Preview text is the second subject line
Clients build the preview from the first text in the body. If that text is the greeting, the preview is the greeting. If the message starts with "I hope this finds you well", that is the preview, and it tells the reader exactly what kind of email this is before they open it. The first sentence should be the reason you are writing — the observation about their company, the specific thing — and the greeting can go on its own line after, or be dropped. Marketing tools solve this with a hidden preheader; in cold email a hidden preheader is a template signal, so the body has to do the job.
What the counts mean
Three to seven words in the subject reads as a person; twelve reads as a campaign. Under fifteen characters can read as a phishing probe unless the sender name carries the trust. The truncation points here are working figures — they shift with device width and font — but they are close enough that a subject which survives the Gmail mobile row will survive everywhere.
What this does not check
Whether the message lands. Copy is one input; authentication, warmup, volume and list quality are the others, and they matter more. The spam word checker scores the full message, and the deliverability score grades the domain. Use this one for the row.
Frequently asked questions
How long should a cold email subject line be?
Under 40 characters and three to seven words, so it survives Gmail mobile and iPhone intact and reads like a note from a colleague.
What is preview text?
The snippet of body text clients show next to or under the subject. Gmail, Outlook and Apple Mail all take it from the first text in the message unless a preheader is set.
Should I use a hidden preheader in cold email?
No. Hidden preheaders are a marketing-template pattern that filters recognise. Make the first sentence of the body carry the point instead.
Are the truncation points exact?
They are typical values for default fonts and common screen widths. Real cut-offs vary by a few characters either way.
Does the tool send anything?
No. Everything renders in your browser.
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