Email on Acid vs Testmail.app
On the evidence we track, Testmail.app leads this comparison with a composite score of 82/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.
Capabilities
Feature-by-feature on the axes that matter for email testing dev. “-” means undocumented, not absent.
What each one is
The product in its own terms, so the numbers below have context.
Email on Acid
Tests email campaigns across 100+ email clients and devices to identify rendering issues, validate content for inbox compatibility, check accessibility compliance, and detect deliverability problems before sending.
Testmail.app
LeaderProvides temporary, addressable mailboxes and APIs enabling developers to capture and verify emails in automated test workflows and CI/CD pipelines without contacting real users.
Pricing
List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.
Email on Acid
From $99/month. 7-day free trial.
- Basic$99/month, $0.15 per preview overage
- 1,000 email previews per month
- 100+ email preview clients and devices
- Unlimited users
- API access
- Overage charges for additional previews
- Premium$199/month
- 2,000 email previews per month
- 100+ email preview clients and devices
- Unlimited users
- Accessibility tests (WCAG 2.2 / European Accessibility Act compliance)
- HTML code analysis
- +2 more
- CustomContact sales
- Custom preview allotments
- Phone and chat support
- Dedicated support documentation
Testmail.app
LeaderFrom free to $299/month. Free tier with 100 emails/month. 14-day trial.
- FreeFree
- 100 emails/month
- Unlimited users, email addresses, and mailboxes
- Essential$12/month or $9/month billed annually
- 10,000 emails/month
- Full API access
- Pro$39/month or $29/month billed annually
- 50,000 emails/month
- Unlimited custom namespaces
- Visual email viewer
- Priority support
- Enterprise$129/month or $89/month billed annually
- 1,000,000 emails/month
- SSO with SAML 2.0 or OIDC
- SCIM support
- Enterprise invoicing
- 99.99% uptime SLA
- Unlimited$299/month or $269/month billed annually
- 10,000,000 emails/month
- All Enterprise features
- Unlimited custom domains
- Custom contracts with enterprise compliance support
Platform & deployment
Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.
Integrations
What each product connects to. Counts come from the vendor's own integration directory where one exists.
Email on Acid
Not documented yet.
Testmail.app
Leader- Microsoft Entra ID
- Okta
- OneLogin
Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.