Substack / Other Newsletter Platforms vs Kit (formerly ConvertKit)
Estimate what moving from Substack / Other Newsletter Platforms to Kit (formerly ConvertKit) costs over 12 to 36 months, including the one-time switch. Then remap your exported CSV headers.
Why teams look at this switch: Revenue-share platform fees compared with Kit plans
Cost calculator
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Default rates are Tiersova placeholders for a typical setup, not published Substack / Other Newsletter Platforms or Kit (formerly ConvertKit) prices. Replace them with your own quote.
CSV header mapper
Rename exported Substack / Other Newsletter Platforms column headers to suggested Kit (formerly ConvertKit) column names, for reporting or manual data preparation. Not an official Kit (formerly ConvertKit) import format. It runs in your browser. Headers are renamed and the values in kept columns stay unchanged; columns that look like passwords or other secrets are removed.
Renamed headers do not make a file import-ready. Check whether and how Kit (formerly ConvertKit) accepts such data before importing, and create any custom fields there first. For contact lists, check opt-out and unsubscribe status separately before importing.
| Substack / Other Newsletter Platforms column | Kit (formerly ConvertKit) column | Field type |
|---|---|---|
| email_address | Suggested | |
| name | first_name | Suggested |
| subscription_type | tags | Suggested |
| created_at | created_at | Suggested |
| stripe_connected | member_status | Consent or status, verify opt-outs |
When moving to Kit (formerly ConvertKit) makes sense
- The comparison above shows a saving at your own volume, after the switching cost.
- Your team can finish the CSV import and onboarding within the switching budget you entered.
- You have checked that Kit (formerly ConvertKit)'s plan covers the integrations and compliance rules you need.
When staying on Substack / Other Newsletter Platforms is the better call
- The one-time migration, re-integration or retraining cost is larger than 12 to 24 months of savings.
- You are inside a multi-year Substack / Other Newsletter Platforms contract with early-termination fees.
- Your workflow relies on add-ons or features Kit (formerly ConvertKit) does not support yet.
How the result changes with volume
Twelve-month totals at half, the same and double the volume you entered above, with the other settings you chose (plan, billing, multiplier, switching and extra costs).
| Volume (Paid & Free Subscribers) | Substack / Other Newsletter Platforms | Kit (formerly ConvertKit) | 12-month difference |
|---|---|---|---|
| 50% volume (7,500) | $238/mo | $70/mo | +$1,166 |
| Your volume (15,000) | $425/mo | $115/mo | +$2,870 |
| 200% volume (30,000) | $800/mo | $205/mo | +$6,290 |
≈ = above the last published price tier, so the amount is extrapolated.
Questions
How is the total cost of Substack / Other Newsletter Platforms and Kit (formerly ConvertKit) compared?
Each side's monthly cost is multiplied by the months in the horizon, and the one-time switching cost is added to Kit (formerly ConvertKit). At the default volume (Paid & Free Subscribers: 15,000), the model gives about $425 per month for Substack / Other Newsletter Platforms and $115 per month for Kit (formerly ConvertKit).
How do Substack / Other Newsletter Platforms CSV headers map to Kit (formerly ConvertKit)?
The mapper renames Substack / Other Newsletter Platforms columns (email, name, subscription_type, created_at, stripe_connected) to Kit (formerly ConvertKit) columns (email_address, first_name, tags, created_at, member_status) in your browser. Custom fields must exist in Kit (formerly ConvertKit) before you import.
When should a company stay on Substack / Other Newsletter Platforms?
Stay if the one-time switching, integration or contract-exit cost is larger than the savings over the horizon you care about. The calculator shows that case as a negative result.