ConvertKit vs. MailerLite vs. Brevo: which ESP for under 5,000 subscribers

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Daily field notes on deliverability, AI tools, hosting, and monetisation. No "top 10 plugins" filler — real tools, real numbers, real failures.

If you’re running a content business with fewer than 5,000 subscribers, your email platform choice matters more for cash flow than features. Most operators overpay for automation they don’t use, or underpay and hit walls when they need basic segmentation.

Here’s how ConvertKit, MailerLite, and Brevo stack up when you’re still small enough that every $20/month counts.

Pricing structure and breakpoints

ConvertKit starts at $25/month for up to 1,000 subscribers on the Creator plan, jumping to $41/month at 1,500, then $66/month at 3,000. By 5,000 subscribers you’re paying $108/month. The free tier caps at 1,000 subscribers but strips out automation—useless if you’re trying to build evergreen onboarding sequences.

MailerLite offers a free tier up to 1,000 subscribers with full automation included. Paid plans start at $10/month for 1,000, rising to $21/month at 2,500 and $32/month at 5,000. The pricing curve is gentler, and you keep all core features on the free plan.

Brevo (formerly Sendinblue) bills by emails sent per month, not subscriber count. The free tier allows 300 emails/day—9,000/month. Paid plans start at $25/month for 20,000 emails. If you send weekly to 4,000 people, that’s 16,000 emails/month—you stay on the free plan. If you send daily, you’ll need paid. This model favors infrequent senders or operators with large lists who broadcast sparingly.

Automation and segmentation depth

ConvertKit’s visual automation builder is powerful but quirky. You can trigger sequences based on link clicks, tag applications, and custom field changes. The interface uses a node-based flowchart that gets messy past five branches. Segmentation works well—you can combine tags with custom fields using AND/OR logic.

MailerLite’s automation editor is cleaner and faster to navigate. You get the same trigger options—email opens, link clicks, field updates—but the UI feels less cluttered. Segmentation is solid for basic use cases; advanced operators occasionally hit limitations when stacking multiple conditions with date-based rules.

Brevo’s automation is the weakest of the three. You can build workflows, but the trigger options are limited compared to ConvertKit and MailerLite. Segmentation exists, but the interface is clunky. Brevo’s strength is transactional email and SMS—if you need those, it’s worth the automation trade-off. If you’re purely running a newsletter with welcome sequences, it’s less compelling.

Deliverability and sending infrastructure

All three platforms maintain strong sender reputations, but configuration matters. ConvertKit and MailerLite both enforce domain authentication (SPF, DKIM) and make setup straightforward. Brevo does the same but adds SMTP relay options if you want to route transactional mail separately from campaigns.

Real-world deliverability is hard to benchmark because it depends on your list hygiene and engagement patterns. Operators report similar inbox rates across all three when lists are clean. The bigger risk is your sending behavior—if you import a cold list or blast infrequently, any platform will land you in spam.

One edge case: MailerLite’s free tier includes its own branding in email footers unless you upgrade. ConvertKit and Brevo don’t add branding on free plans. If you’re staying free long-term, factor that in.

Who each platform suits best

Pick ConvertKit if you’re running a creator business with complex funnels—lead magnets feeding into paid courses, tag-based product recommendations, or multi-step nurture sequences. You’ll pay more, but the automation flexibility justifies it once you’re past 2,000 subscribers and actively monetizing.

Pick MailerLite if you want full-featured email marketing without the ConvertKit premium. The free tier is legitimately usable, and the paid pricing scales gently. Best for newsletters, simple product launches, and operators who need automation but don’t want to spend $100/month yet.

Pick Brevo if you send infrequently to a large list, need transactional email alongside campaigns, or want to add SMS down the road. The send-based pricing model is unusual but powerful for the right use case. Weakest choice if your primary need is sophisticated email automation.

One thing to check before you commit

All three platforms let you export your subscriber list as CSV, but automation export varies. ConvertKit and MailerLite let you duplicate and export sequences as templates. Brevo’s automation workflows don’t export cleanly—if you rebuild on another platform later, you’ll recreate them manually.

If you’re just starting out and expect to migrate in 18 months, that’s not a dealbreaker. If you’re planning to stay put and scale, check the exit path before you build 20 automations.

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The newsletter for newsletter operators

Daily field notes on deliverability, AI tools, hosting, and monetisation. No "top 10 plugins" filler — real tools, real numbers, real failures.

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