MailTester.ninja vs ZeroBounce (2026): which should you pick?
As of Nov 13, 2026, ZeroBounce grades higher than MailTester.ninja: 2.4 against 2.2 out of 4.0.
Checked Oct 18, 2026 and Nov 13, 2026 · graded Oct 18, 2026 and Nov 13, 2026 by ToolGPA
MailTester.ninja grades higher on value for money. ZeroBounce grades higher on features and ease of use. They get the same grade on the free plan and platforms.
Price, platforms and features side by side. The table says where each price was read and when.
MailTester.ninja
Real-time email verifier and finder with a REST API
ZeroBounce
Email list verification with warm-up and DMARC monitoring in one plan
Which one is for you
Pick MailTester.ninja if
- Fits if you want a steady stream of live checks from an API
- Works for people who check a few addresses by hand on the free site
Look elsewhere if
- Tight if you work in bursts, as requests over the daily limit are refused until the next day
- Skip it if you want credits that carry over, since plans are priced by daily limit
- Watch out: Starter is billed weekly, and the monthly plans are Pro and Ultimate
- Watch out: free API calls are 10 or 50 a day, one every 30 seconds
- Watch out: a catch-all domain's accepted address is not proof the mailbox exists
Pick ZeroBounce if
- Fits if you want list cleaning, warm-up and DMARC for one domain on one bill
- Works for developers who want an API with SDKs in 16 languages, or checks from an iPhone or iPad
Look elsewhere if
- Pricey if you only need a list cleaned, at about $129 for 10,000 checks
- Tight if you send from several domains, as ONE watches DMARC for just one
- Watch out: unused tests, monitors and warm-up seeds on ONE don't roll over, only verification credits do
- Watch out: the free 100 checks a month need a business email domain at sign-up
- Not for you if you're on Android or a desktop, as the only app is for iPhone and iPad
How we grade them
| 2.2GPAMailTester.ninjaFair | 2.4GPAZeroBounceFair | |
|---|---|---|
| Value for money | CPro is $23.99 a month, and the weekly Starter is $6.99, about $30 a month. The category's middle is $23. | DAbout $129 for a one-off pack of 10,000 checks, or $79 a month billed yearly on ONE for 10,000 credits a month with warm-up and DMARC included. Its listed rivals charge $39 to $70 for 10,000, so even ONE is the dearest way to check a list. |
| Free plan and trial | COne-off checks on the site are free with no signup. The free API allows 10 checks a day, or 50 with a 7-day token, one request every 30 seconds. | CA free plan: 100 checks a month that refill, plus one inbox test, one server test and one blacklist monitor. You need a business email to get it, and 100 checks won't clean a list. |
| Features | CLive mailbox check, verdict codes, finder and tools. An accepted address on a catch-all domain cannot be confirmed to exist. | BIt covers all three jobs: validation with spam-trap and abuse flags, AI scoring and an email finder, then on ONE, warm-up seeds, 100 inbox tests, blacklist monitors and DMARC reports. DMARC covers just one domain, though. |
| Ease of use | CNo rating on record. Paste an address or call the API; the daily-limit model needs some thought. | BNo App Store rating on record. The core job needs nothing set up: upload a list and download it cleaned. There's an iPhone and iPad app for checking lists away from your desk, too. |
| Platforms and integrations | BWeb only, but with a REST API, SDKs, an MCP server and a list of integrations. | BWeb and an iOS app, an API with SDKs in 16 languages and an MCP server, plus Mailchimp and Zapier. No Android or desktop app. |
| Best for | checking addresses through a daily-limit API | list cleaning with warm-up and DMARC on one bill |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: MailTester.ninja and ZeroBounce. How we grade
Where they differ
- ZeroBounce also covers inbox warm-up and dMARC.
At a glance
| MailTester.ninja | ZeroBounce | |
|---|---|---|
| Pricing | Free plan | Free plan |
| Starts at | $6.99 per week for up to 100,000 checks a day; $23.99 per month for the same limit | $39 one-time for 2,000 verification credits |
| Free plan | One-off checks on the website are free with no signup. The API allows 10 checks a day with key=free, or 50 a day with a free token valid for 7 days. | Freemium: 100 verification credits a month for sign-ups with a business email domain, plus 1 inbox test, 1 server test, 1 blacklist monitor and 10 Email Finder searches. No warm-up or DMARC. |
| Free trial | None listed | None listed |
| Web | ||
| iOS | ||
| Made by | Unlimited & Limited | ZeroBounce |
| Price read from | mailtester.ninja | zerobounce.net |
| Checked | Nov 13, 2026 | Oct 18, 2026 |
Worth knowing
MailTester.ninja
- Free API calls are limited to one request every 30 seconds, and 10 or 50 checks a day.
- Plans are priced by a daily limit, not a credit balance: requests above it are refused until the next day.
- Starter is billed weekly; the monthly plans are Pro and Ultimate.
- An accepted address on a catch-all domain cannot be confirmed to exist.
ZeroBounce
- Warm-up and DMARC monitoring come only with ZeroBounce ONE, and it covers a single DMARC domain.
- Unused tests, monitors, searches and warm-up seeds on ONE do not roll over; only verification credits do.
- The FAQ says credits never expire with an active ONE subscription; otherwise expiry rules may apply depending on when they were bought.
- The free credits need a business or premium email domain at sign-up.
Key features
MailTester.ninja
- Live mailbox check
- Each address is tested against the recipient's mail server (syntax, DNS, MX and an SMTP handshake). No message is sent, and the page says no copy of the address is kept.
- Verdict codes
- Results are ok, ko (invalid) or mb (unverifiable), with messages such as Catch-All, Disposable, Greylisted, Timeout and No MX.
- Email finder
- Tries common address formats such as first.last and flast for a name and company domain, and returns the first the server accepts. The Finder API needs a paid key.
- REST API, SDKs and MCP server
- Two endpoints, an OpenAPI 3.1 spec, JavaScript and Python SDKs and an MCP server for AI agents.
- Deliverability tools
- The site also offers a domain audit report, a sender score test for a sent email and a blocklist checker.
ZeroBounce
- Email validation
- Checks lists by file upload or real-time API and flags invalid, catch-all, disposable, role-based, abuse and spam-trap addresses. Unknown results and duplicates are free.
- AI scoring
- An AI model scores each address for quality at one extra credit, which helps decide whether to send to catch-all and other uncertain addresses.
- Email Finder
- Finds a person's work address from a name and company domain, at 20 credits per successful search; unknown results cost nothing.
- Warm-up and placement tests
- ZeroBounce ONE includes warm-up through a seed network, inbox placement tests against 20+ providers and email server tests.
- Blacklist and DMARC monitoring
- Monitors IPs and domains on blacklists and gathers daily DMARC reports for one domain on the ONE plan.
- API, SDKs and iOS app
- A validation and scoring API with SDKs in 16 languages, an MCP server, and an iOS app for checking lists from an iPhone or iPad.
Plans
MailTester.ninja
Starter$6.99
per week, billed weekly
Up to 100,000 verifications and 100,000 API calls a day. Cancel any time.
Pro$23.99
per month, billed monthly
Up to 100,000 verifications and 100,000 API calls a day.
Ultimate$39.99
per month, billed monthly
Up to 200,000 verifications and 200,000 API calls a day. A quantity above 1 multiplies the limit, so 5 gives 1 million a day.
ZeroBounce
Freemium$0
100 verification credits that refill each month, one inbox placement test, one server test and one blacklist monitor.
Pay-As-You-Go$39
one-time for 2,000 credits
The minimum purchase. Per-credit rates fall with volume: about $129 for 10,000 ($0.0129 each) and $0.0032 each at 1 million.
ZeroBounce ONE$79
per month for 10,000 credits, billed annually ($99 monthly)
Credits roll over, plus 250 warm-up seeds, 100 inbox tests, 100 server tests, 10 blacklist monitors, 1 DMARC domain and 15% off extra credits.
EnterpriseCustom
Purchases or subscriptions of more than 1 million credits, with onboarding and training.
Ways to pay less
MailTester.ninja
No public discounts listed.
ZeroBounce
- Annual discount
20% off ZeroBounce ONE billed annually
ZeroBounce ONE costs $79 a month when paid annually in one charge, against $99 billed monthly.
Common questions
Which is cheaper, MailTester.ninja or ZeroBounce?
As of Nov 13, 2026, MailTester.ninja starts at $6.99 per week for up to 100,000 checks a day; $23.99 per month for the same limit, and ZeroBounce starts at $39 one-time for 2,000 verification credits.
Which has a free plan, MailTester.ninja or ZeroBounce?
As of Nov 13, 2026, both MailTester.ninja and ZeroBounce have a free plan.
Which platforms do MailTester.ninja and ZeroBounce run on?
As of Nov 13, 2026, only ZeroBounce lists an iOS app. Both list a web app. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.