Side by side

Mailosaur vs testmail.app

Both stand on email testing software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.

Mailosaur

Free trial APIWeb

Mailosaur combines message capture, workflow testing, previews and API access for email and SMS quality checks. Its plan structure and inbox limits should be reviewed before choosing a tier.

Visit Mailosaur

Choose testmail.app if your tests need API-retrievable email, dynamically created mailboxes, and documented examples for common testing tools. The free tier has a 100-email monthly allowance and one-day retention; teams needing advanced filters through the simple JSON API will need to use GraphQL instead.

Visit testmail.app

The facts

	Mailosaur	testmail.app
Free plan	A free trial	Yes
Open source	Not published	No
Runs on	API, Web	API, Web
Lowest paid plan	Personal: $20 a month	Essential: $9 a month
Plans published	3	6
Maker	Not published	Not published
Website	mailosaur.com	testmail.app
On email testing software	#23 of 28	#19 of 28

Mailosaur: what it does well

Tests email and SMS workflows end to end
Previews rendering on real devices
Checks accessibility, links and email-client compatibility
Official clients cover eight listed languages
14-day trial available

What to know first

No free plan
Personal plan includes one inbox
External sending requires recipient consent verification
Enterprise pricing is custom

testmail.app: what it does well

Creates mailboxes on the fly using address tags.
Offers JSON and GraphQL APIs with multiple client examples.
Supports wildcard search, live queries, sorting, and pagination.
Includes attachments and SpamAssassin reports.
Unlimited collaborators are allowed on every plan.

What to know first

The free plan allows 100 emails per month.
Free-plan email retention is one day.
Advanced filters and custom sorting are GraphQL-only.
Messages above 20 MB are automatically rejected.

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