Most solo operators start with a free email platform tier and assume they’ll upgrade when subscriber count crosses the threshold. Reality: you’ll hit a different limit first—and the platform will lock or bill you before you notice.
Here’s what actually ends the free ride on three popular platforms, and what you need to watch besides subscriber count.
ConvertKit: 1,000 subscribers, but sends matter more
ConvertKit’s free tier caps at 1,000 subscribers. Clean enough. But the real constraint is the broadcast limit: you can send to your entire list once per day. Automations don’t count against this, but any manual broadcast does.
If you publish daily, you’re fine. If you send a Monday newsletter, a Wednesday product launch, and a Friday recap? You’ll hit the send wall mid-week, and ConvertKit will prompt you to upgrade or wait 24 hours.
The free tier also strips out advanced reporting. You get open rates and click rates, but no link-level breakdowns, no subscriber timezone data, and no A/B test variants. For most operators under 1,000 subscribers, that’s acceptable. For anyone testing subject lines or running cohort experiments, it’s a blocker.
Paid plans start at $15/month for up to 300 subscribers (previously $9 in 2024, increased January 2025), then jump in $10–$15 increments as you grow. The 1,001–1,500 bracket costs $29/month. Billing is monthly by default; annual saves roughly 15%.
Upgrade trigger: You’ll outgrow the single daily send limit before you outgrow 1,000 subscribers—especially if you batch content or run launch sequences.
Brevo: unlimited contacts, but sends cap at 300/day
Brevo (formerly Sendinblue) flips the model. The free tier allows unlimited stored contacts but caps you at 300 emails per day. Not 300 per broadcast—300 total sends, across all automations, transactional messages, and campaigns combined.
If your list is 400 people and you send a single broadcast, you’ll burn your daily budget and leave 100 subscribers undelivered until tomorrow. Brevo queues the remainder automatically, but your “send now” broadcast becomes a two-day trickle.
This structure works if your list is large but inactive, or if you’re using Brevo primarily for transactional email (order confirmations, password resets) and occasional campaigns. It breaks fast for anyone publishing on a schedule.
The entry paid tier is $9/month for 5,000 sends. After that, Brevo bills by send volume, not subscriber count: 10,000 sends costs $18/month, 20,000 sends costs $27/month. If you send daily to 2,000 subscribers, you’ll pay for 60,000+ sends per month—around $49/month.
Upgrade trigger: Daily send volume, not list size. A 500-subscriber list publishing five times a week will need paid access within two weeks.
MailerLite: 1,000 subscribers, 12,000 emails/month
MailerLite’s free tier combines both caps: up to 1,000 subscribers and up to 12,000 emails sent per month. That’s roughly 12 sends to your full list, or 3 sends per week if you’re at cap.
The dual limit is easier to predict than Brevo’s daily throttle, but it penalizes frequent senders. If you publish twice a week and run a 4-email welcome automation, you’ll chew through 10,000+ sends monthly even with 800 subscribers.
MailerLite’s free tier includes A/B testing (subject line only), basic segmentation, and landing page builders—more than ConvertKit offers for free, less than Brevo’s CRM-adjacent features.
Paid plans start at $9/month for up to 500 subscribers (increased from $10/month for 1,000 in mid-2025), then scale in $5–$10 steps. The 1,001–1,500 bracket costs $18/month. Billing is monthly; annual plans save 30%, one of the steeper discounts in this category.
Upgrade trigger: Monthly send volume if you publish frequently, subscriber count if you grow fast but send infrequently.
What actually forces the upgrade
Across all three platforms, the advertised subscriber cap rarely matches the real constraint:
- ConvertKit: broadcast frequency
- Brevo: daily send ceiling
- MailerLite: monthly send budget
If you’re starting out, assume you’ll need paid access once you cross 500 active subscribers and publish more than twice a week. The free tier math breaks earlier than the marketing page suggests.
One more gotcha: all three platforms count failed sends (hard bounces, spam complaints) toward your monthly or daily limit. A stale list will burn through your budget faster than a clean one.
If you’re already on a free tier and approaching limits, audit your unengaged segment now. Removing inactive subscribers before you hit the cap can buy you another month or two—and lower your first paid bill when you do upgrade.
Want more operator-focused breakdowns like this? Subscribe to One Two Three Send for tools, tactics, and pricing reality checks—no fluff, no sponsorships, just what works.
Heads up — some links in this article are affiliate links. If you sign up through them, we may earn a small commission at no extra cost to you. We only recommend tools we use ourselves.