AI Tools
PremiumGenerate Email Subject (AI)
Premium AI email subject ideas in professional, casual, urgent, or creative styles.
About AI email subject lines
Paste the body of your email, or a few lines about what it says, and pick a voice: Professional, Casual, Urgent or Creative. The AI writes five subject lines, each under 60 characters and each taking a different angle: one direct and informative, one phrased as a question, one with urgency, one built around the benefit to the reader and one that plays on curiosity. Five different angles make a good starting point for an A/B test, which most email platforms support: send two subject lines to small parts of your list and mail the winner to everyone else. Look at the preview text as well, the snippet many inboxes show next to the subject, because readers take the two in together. It's a premium tool with one free lifetime trial per account, then Basic with 200 AI requests a month or Pro with 500; one click returns all five lines as a single request. Input is capped at 1,500 tokens including the instructions, about 4,000 characters, so a long newsletter may need trimming to its main points first. Your text goes to Astroworld's server and an AI language model.
Frequently asked questions
What length should an email subject be?
Short enough that the important words show before the inbox cuts it off, which happens sooner on phones than on a desktop. Every line from this tool stays under 60 characters. Put the words that matter at the start so a trimmed subject still makes sense.
Should I use emoji?
Test it on your own list. An emoji can help a subject stand out in a busy consumer inbox, but it looks out of place in most business mail and cold outreach, and not every email app displays every emoji the same way.
Which voice should I choose?
Professional for clients, partners and anything formal. Casual for newsletters and people who know you. Urgent only for real deadlines, like a sale that ends or an account that expires, because readers learn to ignore constant urgency. Creative for launches and campaigns where standing out matters more than plain clarity.
Will subject lines like these land in spam?
Spam filters look at much more than the subject line: your sending reputation, authentication with SPF, DKIM and DMARC, and how recipients respond. A subject in all caps or stuffed with words like FREE doesn't help, which is why the Urgent voice is told to avoid them.