LinkedIn InMail messages have a 1,900-character limit for the message body and 200 characters for subject lines. However, shorter InMails perform significantly better, with messages under 400 characters receiving 22% higher response rates than longer messages. The average InMail gets an 18-25% response rate compared to just 3% for regular connection messages, making character optimization essential for maximizing your limited InMail credits.

This guide covers InMail character limits, optimal message lengths, and proven strategies to improve your response rates.

LinkedIn InMail Character Limits at a Glance

Key performance stats:

• InMails under 400 characters: 22% higher response rates
• Average InMail response rate: 18-25%
• Average cold connection request: 3% response rate
• InMail open rate: approximately 85%

These numbers demonstrate why InMail is worth the investment when used strategically. The 85% open rate far exceeds email marketing averages (20-25%), but response rates depend heavily on message quality and relevance.

Understanding InMail Character Limits

Message Body: 1,900 Characters Maximum

LinkedIn caps InMail message bodies at 1,900 characters, which equals approximately 270-320 words depending on your writing style. This limit applies to all InMail types, including those sent through Sales Navigator, Recruiter, and Premium accounts.

What 1,900 characters looks like:

• About 4-5 short paragraphs
• Approximately 3 minutes of reading time
• Enough for an introduction, value proposition, and call to action

However, just because you can use 1,900 characters does not mean you should. LinkedIn’s own research shows that shorter messages consistently outperform longer ones, with the sweet spot falling under 400 characters.

Subject Line: 200 Characters Maximum

InMail subject lines allow up to 200 characters, but most of this space goes wasted. Subject lines truncate in most inbox views, showing only the first 25-50 characters depending on the device and interface.

Subject line display by context:

This means your subject line needs to hook the reader within the first 25 characters. Anything beyond that serves as supplementary context rather than primary messaging.

Character Count Nuances

When counting characters in LinkedIn InMail:

• Spaces count as characters
• Line breaks count as characters
• Emojis typically count as 2 characters each
• URLs display shortened but count at full length
• Mentions (@name) count as full username length

LinkedIn does not provide a built-in character counter in the InMail composer, so you will need to draft messages externally or use a character counting tool to ensure you stay within optimal limits.

Why Shorter InMails Get Higher Response Rates

LinkedIn’s talent blog and multiple third-party studies confirm that brevity dramatically improves InMail performance. The 22% improvement for messages under 400 characters reflects several factors.

Respect for the Recipient’s Time

Professionals receive dozens of messages daily. An InMail that communicates its purpose in under 400 characters shows you respect their time and have thought carefully about what matters. Long, rambling messages signal that you may be difficult to work with.

Psychological impact of message length:

Short messages feel like opportunities, while long messages feel like obligations. When someone opens a brief, focused InMail, they can process it quickly and respond immediately. Long InMails often get flagged for “later” and never revisited.

Mobile Reading Patterns

Over 60% of LinkedIn activity occurs on mobile devices where reading long messages is frustrating. A 400-character InMail fits on a single screen without scrolling, enabling quick comprehension and response.

Mobile vs. desktop reading behavior:

Messages that require scrolling see measurable drops in response rates across both platforms.

Clarity Forces Better Writing

The 400-character constraint eliminates filler and forces you to prioritize your most compelling points. This discipline produces clearer, more persuasive messages. Longer InMails often dilute strong messages with unnecessary background or excessive pleasantries.

Writing High-Converting Subject Lines

Subject lines determine whether your InMail gets opened. With an 85% open rate overall, LinkedIn InMail performs well, but optimizing subject lines can push your open rates even higher and set the right tone for your message.

Subject Line Best Practices

Keep it under 40 characters: Your full subject line should be visible on most devices without truncation. Front-load the most important words in the first 25 characters.

Personalize when possible: Using the recipient’s name, company, or a specific reference increases open rates. Generic subject lines like “Quick question” or “Opportunity” perform poorly.

Avoid spam triggers: Words like “urgent,” “free,” excessive punctuation, and all caps trigger skepticism even in LinkedIn’s inbox.

Create curiosity without clickbait: Reference something specific that makes the reader want to learn more without being misleading about your intent.

Subject Line Formulas That Work

For recruiting:

• “[Name], quick question about [role area]” (35-45 chars)
• “Your [skill] background caught my attention” (40 chars)
• “[Company] team expansion - [role]” (30-35 chars)

For sales:

• “[Company] + [your company] synergy” (25-35 chars)
• “Idea for [specific challenge]” (25-30 chars)
• “Following up on [trigger event]” (30-35 chars)

For networking:

• “[Mutual connection] suggested I reach out” (40 chars)
• “Fellow [shared background] here” (25-30 chars)
• “Your [content/post/talk] resonated” (30-35 chars)

Subject Lines to Avoid

Too generic:

• “Hello”
• “Quick question”
• “Job opportunity”
• “Let’s connect”

Too salesy:

• “AMAZING opportunity inside!”
• “Don’t miss this!!!”
• “10x your revenue”
• “Urgent: Read immediately”

Too long:

• Subject lines over 60 characters that get cut off mid-word
• Multiple sentences in the subject line
• Full pitch attempts in the subject

Structuring Your InMail Message

Even within 400 characters, your message needs clear structure. The most effective InMails follow a three-part framework that delivers value quickly.

The 3-Part InMail Framework

Part 1: Hook (50-75 characters)

Open with something specific to the recipient that shows you did your research. This could reference their recent work, a shared connection, their company news, or their career trajectory.

Part 2: Value Proposition (150-200 characters)

Explain why you are reaching out and what benefit the recipient might gain from responding. Be specific about the opportunity, connection, or information you are offering.

Part 3: Call to Action (75-100 characters)

End with a clear, low-commitment ask. Request a brief call, offer to share more information, or ask a specific question that is easy to answer.

Example Message Structure

Total: 387 characters

[Hook - 73 chars]
Hi Sarah, your presentation at ProductCon on roadmap prioritization was excellent.

[Value - 189 chars]
I lead product at a Series B startup facing similar prioritization challenges with our enterprise clients. Would love to hear how you balance feature requests against strategic initiatives at scale.

[CTA - 95 chars]
Would you have 15 minutes for a quick call this week or next? Happy to work around your schedule.

This message demonstrates research, offers mutual value through peer conversation, and makes responding easy.

InMail Templates by Purpose

Recruiting Template (378 characters)

Hi [Name],

Your [X years] building [specific skill/area] at [Company] caught my attention. We're scaling our [team] at [Your Company] and looking for leaders who understand [relevant challenge].

The role offers [key benefit: comp, equity, impact]. Would you be open to a 15-minute conversation about what you're looking for in your next move?

Sales Outreach Template (356 characters)

Hi [Name],

Noticed [Company] recently [trigger event: funding, expansion, hire]. Congrats!

We help [similar companies] solve [specific problem] - recently helped [reference company] achieve [specific result].

Worth a quick chat to see if there's a fit? If not now, happy to reconnect when timing is better.

Networking Template (342 characters)

Hi [Name],

Came across your [article/talk/post] on [topic] and really appreciated your point about [specific insight]. I'm working on [related project/challenge] and your perspective resonated.

Would love to connect and learn more about your approach. Any interest in a brief virtual coffee?

Informational Interview Template (368 characters)

Hi [Name],

I'm exploring a transition into [field/role] and your career path from [previous role] to [current role] at [Company] is inspiring.

I'd love to learn about your experience making that shift and any advice you'd share with someone earlier in the journey.

Would you have 20 minutes for a quick call? I'll keep it focused and come prepared.

Maximizing InMail Response Rates

Beyond character count, several factors influence whether your InMail gets a response.

Timing Your InMails

Best days: Tuesday through Thursday consistently outperform Monday and Friday for InMail response rates. Avoid weekends entirely.

Best times: Mid-morning (9-11 AM) and early afternoon (1-3 PM) in the recipient’s timezone see highest engagement. Avoid early morning and late evening sends.

Worst timing: Friday afternoons, Monday mornings, and holiday periods see response rates drop 15-25% compared to optimal windows.

Personalization Depth

Level 1 - Basic (15% lift): Using their name and company in the message.

Level 2 - Relevant (25% lift): Referencing their role, industry, or general background.

Level 3 - Specific (40% lift): Mentioning their recent content, projects, career moves, or shared connections.

Level 3 personalization requires more research but delivers dramatically better results. Spending 5 minutes on research often saves multiple InMail credits on follow-ups.

Follow-Up Strategy

LinkedIn allows sending follow-up InMails to non-responders. The optimal follow-up approach:

First follow-up: 5-7 days after initial message. Keep it shorter than the original (under 200 characters). Add new information or a different angle.

Second follow-up: 2-3 weeks after first follow-up. Offer an easy out (“If timing isn’t right, no worries”) while leaving the door open.

After no response: Move on after two follow-ups. Continued messaging damages your reputation and wastes credits.

Profile Optimization Impact

Your LinkedIn profile is your landing page when someone considers responding. InMails from profiles with professional photos, complete summaries, and relevant experience get 40% higher response rates than sparse profiles.

Profile elements that impact InMail success:

• Professional headshot (36% more views)
• Compelling headline with clear value
• Complete work history with achievements
• Recommendations from relevant contacts
• Recent activity showing engagement

Common InMail Mistakes

Writing Too Much

The biggest mistake is ignoring the data on message length. Long InMails feel like homework assignments and get skipped. If you cannot make your case in 400 characters, you probably do not have a clear enough proposition.

Being Too Vague

Generic messages like “I’d love to connect to discuss opportunities” provide no reason to respond. Specificity shows effort and relevance.

Asking for Too Much

Requesting a 60-minute call, multiple actions, or immediate decisions creates friction. Start with small asks that are easy to accept.

Ignoring Mobile Experience

Formatting that looks clean on desktop may become wall-of-text on mobile. Use short paragraphs and line breaks for readability across devices.

Failing to Research

Sending clearly templated messages without personalization wastes InMail credits and damages your professional reputation. Recipients can tell when they are receiving a mass message.

Frequently Asked Questions

How many characters are allowed in LinkedIn InMail?

LinkedIn InMail allows 1,900 characters for the message body and 200 characters for the subject line, totaling 2,100 characters maximum. However, messages under 400 characters receive 22% higher response rates.

What is the ideal InMail length for recruiting?

Recruiting InMails should stay under 400 characters. Include a specific observation about the candidate, the key opportunity benefit, and a clear call to action for a brief conversation.

Do InMail credits get refunded for responses?

Yes, LinkedIn refunds InMail credits when recipients respond within 90 days, even if the response is a rejection. This makes targeting and personalization even more important, as poor response rates cost credits.

Should I use LinkedIn InMail or regular messages?

Use InMail for reaching people outside your network with important, well-crafted messages. Use regular messages for existing connections where InMail credits would be wasted.

Why is my InMail response rate low?

Low response rates typically indicate messages that are too long, too generic, poorly timed, or reaching the wrong audience. Review your messages for specificity, brevity, and clear value proposition.

Can I use emojis in LinkedIn InMail?

You can use emojis, but use them sparingly and only if appropriate for your industry and the recipient. One well-placed emoji can add personality, while multiple emojis appear unprofessional in most business contexts.

Key Takeaways

• LinkedIn InMail allows 1,900 characters for messages and 200 characters for subject lines, but shorter performs better.
• Messages under 400 characters receive 22% higher response rates than longer messages.
• Subject lines should stay under 40 characters for full visibility across devices.
• Structure InMails with a hook, value proposition, and clear call to action.
• Personalization at the specific level (recent work, shared connections) lifts response rates by 40%.
• Send InMails Tuesday through Thursday, mid-morning or early afternoon in the recipient’s timezone.
• Limit follow-ups to two attempts, spaced 5-7 days and 2-3 weeks apart.

Conclusion

LinkedIn InMail gives you access to decision-makers, candidates, and contacts outside your network, but the 1,900-character limit is a ceiling, not a target. The most effective InMails stay under 400 characters, pack a personalized hook, deliver clear value, and make responding easy. Combined with optimized subject lines under 40 characters and strategic timing, brief InMails consistently outperform longer messages.

Try our free letter counter to ensure your LinkedIn InMails hit the optimal length for maximum response rates.