LinkedIn Message Subject Lines, 15 Examples and Research

What makes a good LinkedIn message subject line?

A good LinkedIn message subject line does three things:

1. It tells one buyer why you are writing to them.
2. It puts that reason in the first few words.
3. It asks for nothing except a few seconds of attention.

"Tomas Novak suggested I write to you" (an invented name) does all three. "Boost your pipeline with our outbound services" fails every one. It hides the reason and pitches before the reader knows who you are.

Independent writing research agrees on the second point. Nielsen Norman Group's guidance on microcontent says a subject line should read as a benefit to the reader or an answer to their need. It should be concise, start with keywords and skip puns and clever wording (NN/g on microcontent).

My own rule sits on top of that. The subject line exists to start one conversation. Conversations come first. Conversations become calls, and calls become clients. So even the first message sells a short meeting only, and the subject line carries no offer and no list of services.

The 15 lines further down were written for this page and never sent, so treat them as patterns to adapt. And the independent research I could find on subject lines comes from email, which makes it a hypothesis for LinkedIn and nothing more.

I also refuse to credit any subject line with a result. Campaign numbers quoted below count accepted requests and booked calls for a whole campaign, and none of them is a subject-line test.

Where does a subject line actually show on LinkedIn?

The clearest written rules cover Message Ads, the paid format many marketers call Sponsored Messages. LinkedIn's Marketing API documentation lists the subject as a required field. It is displayed in the inbox list and in the detailed view of the message (LinkedIn Message Ads API documentation).

The same page separates two kinds of message. InMail between members comes from a person. A Message Ad comes from a brand and includes a call-to-action button.

That changes who is speaking in the subject line. In a sponsored message, a company speaks to a targeted audience. In a member InMail, one named person writes to another, and the reader judges that person.

Two more rules from the documentation matter for anyone writing the copy:

• You can update the sender, subject and body while the creative is a draft. Once it goes live, you cannot change any of them.
• You can trigger a test of a draft, and it lands in your own inbox. Activated creatives then go to a review queue.

Here is the routine I add on top of those rules before any sponsored message goes live:

1. Write the subject after the body and the button text, so all three promise the same thing.
2. Send the test to yourself. Look at the subject in the inbox list on a laptop and on a phone, because that is how a busy buyer sees it first.
3. Ask a colleague who has not seen the draft to read only the subject and say what they expect inside. If they guess wrong, rewrite it.
4. Proofread names, numbers and spelling before activation. After launch, a typo in the subject stays for the life of that creative.

A member InMail has no review queue. Its test is the reader, who will open your profile before answering.

What does the research really say about subject lines?

Most of what anyone knows about subject lines comes from email, so start there and adjust. Cold email has its own examples on a separate page, so this page stays on LinkedIn. My own take on writing them for email is in the journal post on cold email subject lines.

Put the reason first. Both NN/g pieces say the start of the line does the work, because inbox lists cut text off. Put the reason in the first three or four words, and let the rest of the line be the part a phone may hide.

Keep it short, within reason. The Backlinko range is the only length number from real outreach. It shows a correlation between length and replies across millions of sends, with no controlled test behind it. A mid-length line may simply come from senders who write better emails overall.

Personalize with context and leave the first name out. Backlinko found personalized lines did better. The 2023 field experiments found that a first name alone added nothing to opens or clicks. The first-name test went to students from an alumni club.

The surname test went to politicians contacted by a start-up, closer to cold outreach. NN/g adds that a name can make readers feel they are one of thousands. So personalize with something only this reader would recognize: a colleague, a project, a post.

Pick a starting line from the table, then let replies on your own list decide.

Which subject line should I use in my situation?

A vague line wastes attention. If InMail itself is new to you, start with what LinkedIn InMail is. Spend credits only on lines that name a specific reason, and pair each line with a body from the InMail templates.

None of the lines below pitches anything. I keep offers out of opening messages, since an early pitch gets a stranger ignored quicker than any weak wording. The proof goes in the body instead: a past client, a result with a number, a case study the reader can check.

The names and companies are fictional.

Two decision rules come out of the table:

• If you have a real shared contact, use it, because that is the strongest reason a stranger can have to open.
• If all you have is their job title, stop. Go back and find a reason before you spend the credit. A job title is not a reason.

Be careful with example lists that borrow from recruiting. Lines built around "an opportunity" or "your next move" are written for someone who might want a new job. Sent to a buyer, they read like a job offer, or like a hint that you think the buyer should leave. Lines for B2B buyers talk about the work their company is doing.

Why can a great subject line still get no reply?

Because the buyer judges who you are before weighing the wording. Nobody buys from a message. They research you thoroughly before they sign. Copy cannot save a campaign aimed at the wrong buyers, or one sent by someone who looks absent online. Getting the list and the profile right is the core of our LinkedIn outreach work.

One of our campaigns, for a US consulting and coaching firm, ran on LinkedIn outbound plus founder content for 4 months. In one batch of 98 connection requests, 38 were accepted, a 39% connection rate. Month by month the calls climbed: 27, then 35, then 64. Four months in, the total stood at 204 booked sales calls.

Every one of those numbers counts something a buyer did: accepted a request or booked a call. None of them measures a subject line. When a campaign works or fails, the cause usually sits in places a subject line never reaches. More campaign breakdowns are in our case studies.

The first of those places is the sender. A buyer who gets a message from a stranger opens the stranger's profile. I treat that profile as a page written for buyers deciding whether to answer, closer to a landing page than a CV.

An ordinary message from a profile buyers can trust will out-pull a polished message from an empty one. I have seen it in our own numbers. Identical message, two different companies. One company got 2% replies. The other got 7.5%.

So fix things in this order before you touch the subject line:

1. The list. The right companies, and the titles that really decide in that niche.
2. The sender's profile. A headline, an About section and proof that a stranger understands in seconds.
3. The ask. A short meeting, sold with what the buyer gets out of it.
4. The body. One checkable result, inside the message.
5. The subject line. It comes last.

Edit your own draft in that order too. Delete the pitch and the paragraph of company history first, then decide whether the subject line still needs work.

How do I test LinkedIn subject lines without fooling myself?

Start by ignoring opens. Most subject-line advice is built on email open rates, and those are less trustworthy than they look.

Apple's Mail Privacy Protection stops senders from using invisible pixels to learn when someone opens an email (Apple Newsroom, June 2021).

Apple's iPhone guide says the same: with the feature on, senders cannot see whether you opened their message (Apple Support).

Any "winning" line chosen on that data may have won nothing.

Here is a method that works at the volume most founders actually send:

1. Change one thing. Only the subject line differs. The body, the ask, the sender and the send days stay the same.
2. Split one segment. Divide a single list segment at random between the two versions. Never compare a line sent to CFOs with a line sent to site managers.
3. Judge on positive replies and booked calls. A curious "who is this?" is not a win. Count replies that move toward a meeting, then the meetings. For lists too small for clean statistics, see A/B testing on a small list.
4. Wait for enough replies. Call a winner only when one or two more replies could not flip the result. Until then, keep both versions running.
5. Replace the loser. Keep the winner, write a new challenger and start again.

Record every stage, one row per week: messages sent, replies, positive replies, booked calls and calls held. That shows exactly where a change moved something.

A subject line can only touch the reply stage and what follows it, so judge it there, and judge it last.

Anyone who quotes you a reply rate for a single line should be able to show the sample, the window and what else changed. If they cannot, write your own line from the table above, fix the list and the profile first, and let your booked calls pick the winner.

Unsure which of these lines fits the people you message? Book a call and send me three of your recent subject lines. I will say which one I would keep and why.