Quick answer
Mailinator - Mailinator wins for most builders because its free tier covers real workflow testing beyond inbox access, while Free Mail Tester is the better fit only if you specifically need one-off deliverability checks.
How the free tiers compare
These free tiers solve different jobs. Free Mail Tester is a narrow tool for sending a message to a unique test address and getting a deliverability score with DNS, spam, and header analysis. It is simple, anonymous, and unlimited, which makes it good for quick checks and ad hoc debugging. Mailinator is a broader testing platform for email and SMS workflows, with public inboxes on the free plan and a path into private inboxes, APIs, webhooks, routing, and load testing on paid plans. For builders, the choice is less about raw volume and more about whether you need a deliverability scanner or a test harness for sign-up and OTP flows. Mailinator’s free tier is more useful for ongoing QA. Free Mail Tester is lighter and more specialized.
Free Mail Tester vs Mailinator free tier, side by side
| Free Mail TesterFTV 49 | MailinatorFTV 74 | |
|---|---|---|
| Free tier accessA is a deliverability checker, B is a disposable inbox platform. | Unlimited tests | Unlimited public inboxes |
| Signup requiredBoth free tiers can be used without creating an account. | No signup required | No sign-up required |
| Credit card required | No | No |
| Storage on free tierMailinator’s free plan keeps messages temporarily; Free Mail Tester does not list inbox storage. | Not stated | Temporary storage |
| API access on free tierMailinator’s free tier includes API access, webhooks, and routing rules. | Not included / not stated | Included |
| SMS testing on free tierMailinator includes SMS testing on the free plan. | Not included / not stated | Included |
After you outgrow the free tier
Free Mail Tester has no paid tier: the deliverability test at this URL is unlimited and free with no credit packs or subscription. Mailinator’s paid path is a flat monthly subscription for private inboxes and higher workflow limits, starting at $0 with Verification for private access, then $79/month billed yearly for Business. For any volume of deliverability checks, Free Mail Tester stays free; Mailinator’s paid tiers are the relevant upgrade only if you need private inboxes, seats, or workflow tooling.
Cost at real usage
| Usage | Free Mail Tester | Mailinator |
|---|---|---|
| 5,000 validations / monthMailinator’s public free tier is not a validation-credit product, so this is not a direct apples-to-apples workload. | Free | Free (public plan) |
| 25,000 validations / monthFree Mail Tester has no usage cap on its deliverability test. | Free | Free (public plan) |
| 100K messages / monthMailinator’s Business plan includes 100K emails/mo and private inboxes. | Free | $79/mo billed yearly |
| 300K messages / monthMailinator’s Business Plus includes 300K emails/mo. | Free | $159/mo billed yearly |
Estimates, not quotes. Usage-based rates change - verify with the vendor's pricing page before committing.
When to pick each one
Pick Free Mail Tester when…
- You want to check deliverability for a single campaign or message and do not need inbox infrastructure.
- You need a fast, no-signup sanity check on SPF, DKIM, DMARC, blacklist status, or header issues.
- You are debugging why a message landed in spam and want a score plus technical analysis.
- You only need occasional tests and prefer an unlimited free tool over a workflow platform.
Pick Mailinator when…
- You are testing sign-up, login, OTP, or password reset flows end to end.
- You need public inboxes for disposable email QA without creating an account.
- You want API access, webhooks, routing rules, or SMS testing on the free tier.
- You expect to grow into private inboxes, team seats, or higher message volume later.
- You need a shared QA tool that can support broader email workflow testing, not just deliverability scoring.
Bottom line
For the most common builder use case, Mailinator is the better pick because the free tier supports real email and SMS workflow testing, not just deliverability checks. Free Mail Tester is excellent if your need is narrower: send a message, get a score, fix spam or DNS issues, and move on. If you expect to test sign-ups, OTPs, or team QA flows, Mailinator gives you more of the stack for free and a more obvious upgrade path later.
Read the full listings: Free Mail Tester and Mailinator. Scores use the FTV methodology at /ftv. Browse more head-to-heads on /compare, or see the top-ranked free tiers on /top.