How to Write the Best LinkedIn InMail Subject Lines (With 25+ Free Templates)
TL;DR
- The subject line is the single biggest factor in whether your InMail gets opened
- Personalized, specific subject lines outperform generic ones by 26%+
- Keep it under 60 characters, avoid caps and emojis, and never fake urgency
- The five most common subject lines ("Quick question," "Exciting opportunity," etc.) are also the five most ignored
- Test variations across 50+ sends before drawing conclusions
- Outly lets you run personalized InMail campaigns at scale and track what's working
The subject line is the only thing standing between your InMail and the trash.
LinkedIn shows recipients the sender name, the subject line, and a preview of the first sentence. That's it. If the subject line doesn't earn the click, the rest of your carefully crafted message never gets read.
Most people treat the subject line as an afterthought. That's why most InMails get ignored.
What's LinkedIn InMail?
InMail is LinkedIn's premium messaging feature that lets you contact anyone on the platform, even people you're not connected with. Unlike a regular connection request message (capped at 300 characters), InMail gives you up to 1,900 characters and goes directly to the recipient's inbox.
The catch: InMail costs credits. LinkedIn Premium gives you 5 per month. Sales Navigator Core gives you 50. Credits are refunded when someone replies, which means a high response rate stretches your budget further.
That's exactly why the subject line matters so much. Every ignored InMail is a wasted credit.
5 Tips to Write the Best InMail Subject Lines
#1 Curiosity is a dangerous thing — but not here
Curiosity-driven subject lines work when they're grounded in something real. "Your post on AI hiring trends" earns the open because it signals you've actually read their content. "Something you'll find interesting" earns the delete because it signals nothing.
The goal is to make the recipient think "this person knows who I am" — not "this person wants something from me."
#2 Make it about them
The fastest way to get ignored is to lead with yourself. "We're a fast-growing company..." is the most common opener in cold outreach and the least effective. Your subject line should reference their company, their work, their recent milestone, or their specific situation.
"Saw [their company] just raised a Series B" is about them. "Exciting opportunity from [your company]" is about you. One gets opened. The other doesn't.
#3 Keep it short
LinkedIn truncates subject lines on mobile. Most people check LinkedIn on their phones. If your subject line gets cut off mid-sentence, you lose the context that was supposed to earn the click.
Aim for 40-60 characters. That's roughly 6-10 words. Enough to be specific, short enough to survive mobile truncation.
#4 No caps, no emojis, no urgency
"AMAZING OPPORTUNITY!!!" reads like spam. It also looks desperate. All-caps subject lines and excessive punctuation are signals that the sender doesn't trust their message to stand on its own.
Fake urgency ("Time-sensitive," "Don't miss this") is even worse. It might get the open, but it destroys trust the moment the message doesn't match the hype.
Write like a professional reaching out to another professional. Lowercase, no emojis, no manufactured pressure.
#5 Test variations
If you're sending InMails at volume, don't guess which subject line works best. Test two or three variations against each other. Track open rates over 50+ sends before drawing conclusions. Small sample sizes produce misleading data.
Variables worth testing:
- Personalized vs. generic (personalized almost always wins)
- Question vs. statement
- Short (under 40 chars) vs. medium (40-60 chars)
- Trigger event hook vs. profile-based hook
25+ Best LinkedIn InMail Subject Line Examples
Recruiting Subject Lines
These work because they signal relevance and respect the candidate's time.
- "Your [specific skill] background — worth a conversation?"
- "Saw your work at [company] — quick question"
- "Congrats on [recent milestone] — I have a question"
- "[Mutual connection] suggested I reach out"
- "Role that matches your [specific experience]"
- "Your [specific project] caught my attention"
- "Not a pitch — just a conversation about [area]"
- "Following your career in [field] — have a question"
- "Team at [your company] building [relevant thing]"
- "Your background in [X] is rare — worth 15 minutes?"
The best recruiting subject lines do one of three things: reference something specific from their profile, use a mutual connection, or explicitly lower the stakes ("not a pitch").
Sales Subject Lines
Sales InMails need to earn trust fast. The subject line should hint at value, not demand attention.
- "[Their company] + [your company] — worth exploring?"
- "How [peer company] solved [specific problem]"
- "Saw [their company] just [trigger event] — relevant question"
- "Quick thought on [specific challenge in their industry]"
- "[Specific metric] improvement at companies like [theirs]"
- "Question about how [their company] handles [process]"
- "Something I noticed about [their company's] approach to [X]"
- "[Mutual connection] thought we should talk"
- "Relevant to your [specific initiative or announcement]"
- "One thing [competitor] is doing differently"
Trigger events are gold for sales subject lines. A funding round, a new hire, a product launch, a job posting — all of these give you a natural, non-pushy reason to reach out.
Networking Subject Lines
Networking InMails should feel like a genuine human reaching out, not a pitch in disguise.
- "Your talk at [event] — a question"
- "Fellow [industry] person — would love to connect"
- "Your article on [topic] — a follow-up thought"
- "We have [mutual connection] in common"
- "Admired your work on [specific thing] for a while"
- "Quick question from someone in [their field]"
- "Your perspective on [specific topic]?"
- "Saw your comment on [post] — wanted to follow up"
- "Both working on [similar problem] — worth connecting?"
- "Your career path in [area] — can I ask you something?"
The best networking subject lines reference something real and specific. They make the recipient feel seen, not targeted.
Job Seeker Subject Lines
If you're reaching out to a hiring manager or recruiter, your subject line needs to signal value immediately.
- "Experienced [role] — interested in [company]"
- "Your [job posting] — I have relevant experience"
- "Background in [X] — exploring opportunities at [company]"
- "Referred by [mutual connection] for [role]"
- "5 years in [relevant area] — open to a conversation?"
- "Your team's work on [project] — I'd love to contribute"
Don't be vague. "Looking for opportunities" tells them nothing. "3 years in enterprise SaaS sales — interested in your AE role" tells them everything they need to decide if it's worth opening.
What to Avoid
Fake urgency. "Time-sensitive opportunity" and "Don't miss this" are manipulation tactics. They might get the open, but they destroy trust the moment the message doesn't match the hype.
All caps or excessive punctuation. "AMAZING OPPORTUNITY!!!" reads like spam. It also looks desperate.
Vague compliments. "I've been following your impressive career" is so generic it means nothing. If you're going to compliment someone, be specific about what impressed you.
Questions that answer themselves. "Would you like to earn more money?" is technically a question, but it's also condescending. Ask questions that require a real answer.
Your company name in the subject line. Unless you're a household brand, leading with your company name is a missed opportunity. Lead with their name, their company, or their work instead.
Conclusion: Automate Your InMails
The subject line isn't decoration. It's the entire first impression. Get it right and the rest of the message has a chance. Get it wrong and it doesn't matter how good the rest is.
Before you send any InMail, read the subject line out loud and ask: "If I received this from a stranger, would I open it?" If the honest answer is no, rewrite it.
Once you've nailed your subject line formula, the next step is scale. Outly lets you run personalized InMail campaigns across your entire prospect list, track open and response rates by subject line variation, and iterate on what's working. Starter plan starts at $39.99/month. Pro at $79.99/month.
The subject line is the first test. The message is the second. Both matter.
Start your free trial at Outly and put your best subject lines to work.
