Customer.io vs Plunk pricing

Verified 2026-10-24 (1 day ago)Source: Customer.io: customer.io/pricing, Plunk: www.useplunk.com/pricingVerified shows the older of the two.

Monthly cost at three volumes

Monthly cost of Customer.io and Plunk at three volumes and at your own
Volume	Customer.io	Plunk
small5K emails sent	$100 / moEssentials	$5 / moPay as you grow
growing50K emails sent	$100 / moEssentials	$50 / moPay as you grow
scale500K emails sent	$100 / moEssentials	$500 / moPay as you grow
your volumeset above	$100 / moEssentials	$50 / moPay as you grow

Each cell is the cheapest feasible plan, or the chosen model, at that volume, from the shared Overage cost function. "Cheapest model" only considers models with both an input and an output price listed. Volumes are example scenarios you can edit.

Tiers, aligned by position

Tiers of Customer.io and Plunk aligned by position: free, entry, mid, top
Position	Customer.io	Plunk
Free	no tier	$0 / moFree · 1,000 emails sent / mo
Entry	$100 / moEssentials · 1,000,000 emails sent / mo	$0 base + usagePay as you grow
Mid	$1,000 / moPremium	no tier
Top	Contact salesEnterprise	no tier

Tightest rate limit

Tightest documented rate limit of each service
Measure	Customer.io	Plunk
Tightest limit	unlisted	unlisted

Changes in the last 90 days

No changes recorded.

No change detected for either service in the last 90 days.