LetterDuck vs Kit: automation platform or email workspace?
Kit sells automation. We sell a flat bill and a shared inbox. Which one you need depends on whether your newsletter is a funnel or a publication.
What each one is
Kit, which completed its rebrand from ConvertKit in October 2024, is a creator automation platform. The paid Creator plan carries unlimited visual automations and email sequences, integrations, A/B subject testing, and a long-standing deliverability reputation, and the surrounding stack monetizes directly: paid newsletters, digital products, tip jars, and the Creator Network's cross-promotion engine. Its free Newsletter plan is one of the most generous anywhere, covering up to 10,000 subscribers with unlimited broadcasts, landing pages, and forms. Billing counts only unique, active subscribers, so unsubscribes never inflate the bill.
LetterDuck is a flat-rate email workspace. $50 a month buys a whole domain: unlimited addresses (an address is a routing rule, not a seat), a threaded team inbox where anyone replies as any address on the domain, and a newsletter composer with a designed template. Deliverability is the managed part: SPF, DKIM, and DMARC on your domain, a warm-up throttle written into the send path, automatic suppression of bounces and complaints, and RFC 8058 one-click unsubscribe on every campaign. LetterDuck is in waitlist mode today; the form on this page holds a place in line.
What it costs at four list sizes
| Monthly cost at | Kit (formerly ConvertKit) | LetterDuck |
|---|---|---|
| 500 subscribers | $32.50 | $50 flat |
| 1,000 subscribers | $32.50 | $50 flat |
| 5,000 subscribers | $74.17 | $50 flat |
| 10,000 subscribers | $115.83 | $50 flat |
Public list prices, August 2026, annual billing where offered. Kit (formerly ConvertKit): Creator plan on annual billing, which costs ten times the monthly price. On monthly billing the same list sizes cost $39, $39, $89 and $139. LetterDuck is $50 per domain, flat, unlimited addresses and subscribers.
The cost story
Kit prices by list size, and the steps between tiers are the whole story. On monthly billing, Creator runs $39 up to 1,000 subscribers, $59 to 3,000, $89 to 5,000, $119 to 8,000, and $139 to 10,000, continuing up to $2,499 a month at 500,000. Annual billing is exactly ten times the monthly price, two months free, which works out to $32.50, $49.17, $74.17, $99.17, and $115.83 effective per month at the same tiers.
The crossover against our flat $50 sits in an interesting spot. On monthly billing Kit is cheaper only below the 1,000-subscriber line, because crossing it jumps the bill 51%, from $39 to $59. On annual billing the 3,000 tier is $49.17, which undercuts us by 83 cents a month; the real crossover for annual payers is the 3,001st subscriber, where the effective rate becomes $74.17. Run the worked example: a 900-subscriber list growing 300 a month starts at $39, pays $59 within weeks, and reaches the $89 tier inside eight months. By its first anniversary the list sits near 4,500 and the bill has grown 128% on monthly billing. The same year here costs $600, and the 10,000-subscriber year after that also costs $600, against Kit's $1,668 on monthly billing or $1,390 prepaid annually.
Price history deserves a line too. In October 2025 Kit raised Creator's base from $29 to $39 at 1,000 subscribers, a 34% increase with no grandfathering; existing customers moved on their first bill after October 15, 2025. Many 2026 roundups still print the stale $29 table, which is one reason we quote the live price arrays with a date. Wanting the team features, Subscriber Signals, or the referral system moves you to Creator Pro, which runs $189 a month at 10,000 subscribers on monthly billing, nearly double Creator at the same size. How subscriber-tier pricing behaves across the whole industry is charted in our email pricing guide.
The fair counterweight: Kit's free plan covers every list size in our table at $0. If broadcasts, landing pages, and Kit branding are all you need, free beats both paid products on this page, ours included.
Feature by feature
| Capability | Kit | LetterDuck |
|---|---|---|
| Price at 10,000 subscribers | $139/mo monthly billing, $115.83 annual effective | $50/mo flat |
| Free tier | $0 up to 10,000 subscribers | None; waitlisted paid product |
| Visual automations and sequences | Unlimited on Creator | |
| Integrations | On paid plans | |
| A/B subject testing | Creator and up | |
| Creator monetization: products, tip jars, paid newsletters | ||
| Creator Network cross-promotion | ||
| Billing basis | Unique active subscribers only | Subscribers never touch the price |
| Team inbox on your own domain | Threaded, reply as any address | |
| Unlimited addresses on your domain | Included in the flat fee | |
| Unlimited seats without an upsell | Unlimited users is a Creator Pro feature | |
| Deliverability controls you can read | Strong reputation, managed out of sight | Throttle, suppression, and complaint gates in your own send path |
Choose Kit if
- Automations earn your money. Welcome sequences, launch funnels, tag-triggered flows: Kit does this as well as anyone, and we do not do it at all.
- Your stack is wired together. Kit's integrations connect commerce, courses, and forms; LetterDuck offers no integration catalog.
- You sell digital products or paid newsletters and want the storefront inside the email tool, plus the Creator Network finding you subscribers.
- You are under 10,000 subscribers and can live with broadcasts only. The free Newsletter plan is unmatched at that shape.
Choose LetterDuck if
- Your list has crossed 3,000 and keeps growing. From there every Kit tier costs more than $50, and at 10,000 the gap is $66 to $89 a month depending on billing.
- The newsletter is one part of a working inbox. Reader replies, sponsor threads, and support mail all land on your domain here, answerable by anyone on the team from any address, with no seat pricing anywhere.
- You want the deliverability mechanics visible. Our send path ramps a new domain from about 150 sends on day one to roughly 1,100 a day by day seven and halts itself at a 0.3% complaint rate or 2% bounces; those thresholds are enforced in code, not written in a help doc.
- You are a small team rather than a solo operator. Kit's unlimited-users option lives on Creator Pro; here every plan is the plan, and it includes everyone.
Comparing more broadly first? Start with our Kit alternatives roundup.
Migrating from Kit to LetterDuck
Plan one honest afternoon of work plus a week of warm-up, with one hard prerequisite: if active sequences drive your revenue, rebuild that machinery somewhere before you move anything, because it does not exist here.
- Export your subscribers from Kit as CSV, tags included. Kit's export preserves tags, which map cleanly onto LetterDuck's folders and contact notes.
- Import the CSV and recreate your segments as folders. This is manual but small; most creators run far fewer meaningful segments than they have tags.
- Verify your domain with the DNS records we generate, then let the warm-up throttle pace your first sends. The ramp we enforce:
Day 1: ~150 sends
Days 2-6: volume x ~1.4 per day
Day 7: ~2,000 sends/day
- Send the first issue to your most engaged readers, not the whole file. A new sending domain builds its reputation on engagement, and opening with your 90-day actives is the cheapest reputation you will ever buy.
- Sunset Kit only after two clean sends. Keep the account through one billing cycle as a fallback; the export is repeatable, so nothing is lost by overlapping for a month.