Inbox Monster vs MailSlurp
Inbox Monster
inboxmonster.com
MailSlurp
mailslurp.comSide by side
| Figure | Inbox Monster | MailSlurp |
|---|---|---|
| Price from | $312.50/mo | $19.99/mo |
| Free plan | — | Yes |
| Free trial | — | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | — | Yes |
| Plans published | 5 | 9 |
| Spec score · Email Testing Software | 7.6 (#20) | 8.9 (#5) |
| Headquarters | United States | Saue, Harjumaa, Estonia |
| Integrations | Documented integrations include Salesforce Marketing Cloud, Braze, Iterable, SparkPost, Twilio SendGrid and Amazon SES. | The integrations directory lists 79 items, including SDKs, Playwright, Cypress, Selenium, BrowserStack, Zapier, Power Automate, UiPath, Postman, GraphQL and webhooks. |
| Security controls | The Trust Center lists audit logging, data security, multifactor authentication, penetration testing and encryption-at-rest documentation. | The security policy states TLS in transit, AES-256 encryption at rest, AWS RDS/S3 storage, daily backups, VPNs, network ACLs, penetration testing and RBAC. |
Plans
Inbox Monster
- Essential (Creative suite)$3,750 a year
- SMS suite$6,000 a year
- Advanced (Creative suite)$6,500 a year
- Enterprise (Creative suite)$10,000 a year
- Deliverability suite$15,000 a year
MailSlurp
- FreeFree
- FreeFree
- Starter$19.99 a month
- Starter$19.99 a month
- Pro$49.99 a month
- Pro$49.99 a month
- Growth$129.99 a month
- Growth$129.99 a month
- EnterprisePriced on request
In their own words
Inbox Monster
Inbox Monster has no write-up on Specifiction yet; its figures are above.
MailSlurp
MailSlurp provides tools to build, test, and automate email and SMS workflows. Users can create temporary or permanent inboxes and handle messages through APIs, SDKs, SMTP, IMAP, and webhooks. It supports end-to-end tests for scenarios including OTP, MFA, magic links, and load testing, as well as device previews, email audits, and inbox placement checks. Pipelines can route messages and attachments using webhooks, forwarding, and automatic replies. AI extraction can turn emails and attachments such as PDFs and images into structured JSON using prompts, schemas, and OCR. Listed integrations include Playwright, Cypress, Selenium, HubSpot, Braze, Mailchimp, Zapier, and AI assistants through MCP. A REST API and official SDKs cover several programming languages. The free plan has capped allowances, including 500 received emails and 1,000 sandbox sends per month. Starter costs $19.99/mo; custom domains and phone numbers require Pro on Free and Starter plans. MailSlurp is web- and API-accessible.