Warmbly vs Warmup Inbox (2026): which should you pick?
As of Nov 13, 2026, we pick Warmup Inbox: it is second in our ranking of email verification and deliverability tools, and it grades higher too, 2.4 against 2.2.
Checked Oct 18, 2026 and Nov 13, 2026 · graded Oct 18, 2026 and Nov 13, 2026 by ToolGPA
Warmup Inbox grades higher on value for money. They get the same grade on the free plan, features, ease of use and platforms.
Price, platforms and features side by side. The table says where each price was read and when.
Warmbly
Open-source cold email platform with mailbox warmup
Warmup Inbox
Email warm-up through a network of real inboxes, priced per inbox
Which one is for you
Pick Warmbly if
- Fits if you send cold email from several mailboxes and want warmup built in
- Works for teams happy to self-host and read the source
Look elsewhere if
- Skip it if you want a free plan, as there is only a 14-day trial
- Tight if you send in volume, since Starter stops at 150 cold emails a day
- Pricey if you need roles and an audit log, which start at Business, $263 a month
- Watch out: self-hosted warmup only uses the mailboxes you connect, not the shared pool
- Watch out: Agency plans pool sends across clients, and top-up packs cost extra
Pick Warmup Inbox if
- Fits if you're setting up new mailboxes and domains for cold email
- Works for warming a dedicated IP before raising volume, or many client inboxes from one dashboard
Look elsewhere if
- Pricey if you run lots of inboxes, as you pay for every one
- Tight if you write in another language or send through SES or SendGrid, as that warm-up needs Pro at $49 an inbox
- Skip it if you also need list cleaning or DMARC, as only a free record generator is offered
- Watch out: the trial lasts 7 days, and Basic stops at 75 warm-up messages a day with replies up to 25%
- Pricey if you pay monthly, at $19 an inbox against $15 billed yearly
How we grade them
| 2.2GPAWarmblyFair | 2.4GPAWarmup InboxFair | |
|---|---|---|
| Value for money | CStarter is $23 a month billed yearly ($29 monthly), which is the category's middle figure. It covers 150 cold emails a day. | BBasic is $15 an inbox a month billed yearly ($19 monthly), and the price per inbox falls as you add more. That's the lowest price among its listed warm-up rivals: MailReach is $20 a mailbox, Warmy starts at $49 and InboxAlly at $149. |
| Free plan and trial | C14-day trial with no card. There is no free plan. | CNo free plan, but a 7-day trial of any plan with no card. That's a week to look around; after that you pay for each inbox. |
| Features | CWarmup, campaigns, unified inbox, placement tests, CRM and lead finder. The CRM and API need Grow ($71), and each mailbox defaults to 50 sends a day. | CIt does warm-up fully: more than 30,000 real inboxes replying to 25% to 50% of your emails by plan, spam and tab monitoring, IP warm-up and simple outreach sequences. No list cleaning or DMARC, though, and language and SES or SendGrid warm-up need Pro. |
| Ease of use | CNo rating on record. You connect mailboxes, set up warmup and build campaigns, and self-hosting is an option. | CNo App Store rating on record. You connect each mailbox and leave it running before you send, and the settings you'll want, your own templates and topics, sit on Pro. |
| Platforms and integrations | BWeb app with four listed integrations, an API and webhooks from Grow. No desktop or phone app. | BWeb with an API on every plan, working with Gmail, Google Workspace, Outlook, Microsoft 365, Amazon SES, SendGrid and Zoho Mail. No phone or desktop app. |
| Best for | cold email sending with mailbox warmup in one place | warm-up for new cold email inboxes |
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: Warmbly and Warmup Inbox. How we grade
Price against what you get
Warmbly starts at $23 a month and scores 2.3 out of 4 on features, ease of use and platforms. Warmup Inbox starts at $15 a month and scores 2.3.
They score the same, and Warmup Inbox starts $8 a month lower. Of the other email verification and deliverability tools on the chart, 7 score higher than Warmbly for less, and 5 score higher than Warmup Inbox for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- Warmbly is open source and self-hostable, according to its own site.
- Warmbly also covers workflow automation.
- Warmup Inbox also covers email campaigns.
At a glance
| Warmbly | Warmup Inbox | |
|---|---|---|
| Pricing | Free trial | Free trial |
| Starts at | $23 per month, billed yearly ($29 billed monthly) | $15 per inbox / month, billed annually ($19 monthly) |
| Free plan | None | None |
| Free trial | 14-day free trial, no credit card | 7-day free trial of any plan, no credit card required |
| Web | ||
| Made by | Warmbly | CyberPanda s. r. o. |
| Price read from | warmbly.com | warmupinbox.com |
| Checked | Nov 13, 2026 | Oct 18, 2026 |
Worth knowing
Warmbly
- Plans are capped by cold emails a day, with each mailbox limited to 50 a day by default.
- The CRM and API need Grow or above, and team roles and audit log need Business.
- Self-hosted warmup uses only the mailboxes you connect, not the cloud's shared pool.
- Agency plans pool sends across clients; top-up packs of 50,000 sends cost $85 (Agency) or $60 (Agency Pro).
Warmup Inbox
- Pricing is per inbox, so costs grow with each mailbox; volume discounts start from the second inbox.
- Language warm-up, email-platform warm-up and custom templates need Pro or above.
- It does not verify lists or manage DMARC; DMARC help is limited to a free record generator.
Key features
Warmbly
- Mailbox warmup
- Warmup is unlimited on every paid plan and runs in a shared premium pool, ramping each mailbox's daily volume over time.
- Campaigns and unified inbox
- Sequences with follow-ups, branching and A/B tests send across mailboxes, and every reply lands in one inbox with labels.
- Inbox placement tests
- Analytics cover sends, replies, bounces and placement tests, and the dashboard shows a health score for each connected mailbox.
- CRM, lead finder and automations
- A built-in CRM tracks deals and tasks, a lead finder searches OpenStreetMap, and automations act when a reply arrives.
- Self-hosting
- The platform is Apache 2.0 licensed and can run on your own server, where warmup uses only the mailboxes you connect.
Warmup Inbox
- Warm-up network
- Your mailbox exchanges AI-written emails with more than 30,000 real inboxes, which reply to up to 25% to 50% of them depending on the plan.
- Spam and category monitoring
- Dashboards show whether warm-up emails land in spam or in a category tab, plus an email reputation check.
- Language and ESP warm-up
- On Pro and Max, warm up in other languages and through sending platforms such as SendGrid and Amazon SES, with custom templates and topics.
- IP warm-up
- Warms a dedicated sending IP before volume is raised.
- Outreach sequences
- Basic cold email sequences are included, so a warmed inbox can send campaigns from the same account.
- API and free tools
- A developer API on every plan, plus free placement tests, blacklist checks and DMARC and SPF record generators.
Plans
Warmbly
Starter$23
per month, billed yearly ($29 billed monthly)
150 cold emails a day, up to 4,500 a month; unlimited mailboxes and warmup, community support.
Grow$71
per month, billed yearly ($89 billed monthly)
3,000 cold emails a day, up to 90,000 a month; adds CRM, API and webhooks, email support.
Business$263
per month, billed yearly ($329 billed monthly)
15,000 cold emails a day, up to 450,000 a month; team roles, audit log, priority support.
Agency$199
per month, billed yearly ($249 billed monthly)
150,000 sends a month shared by unlimited clients, with a white-label portal and $10 of shared AI.
Agency Pro$479
per month for 500,000 sends, billed yearly ($599 billed monthly)
Full white-label; 500,000 sends a month shared by every client, $30 of shared AI.
EnterpriseCustom
Over 15,000 cold emails a day, custom contract and dedicated support; sold through sales.
Warmup Inbox
Basic$15
per inbox / month, billed annually ($19 monthly)
75 warm-up messages a day, reply rate up to 25%, spam and category monitoring, outreach sequences and the API. The per-inbox price falls as inboxes are added.
Pro$49
per inbox / month, billed annually ($59 monthly)
250 warm-up messages a day, replies up to 45%, your own templates and topics, language and email-platform warm-up, and scheduling.
Max$79
per inbox / month, billed annually ($99 monthly)
1,000 warm-up messages a day, replies up to 50%, a technical setup check, premium support and unlimited API use.
51+ inboxesCustom
Quoted pricing with multi-client workspaces, consolidated billing, specialized reports and dedicated onboarding.
Ways to pay less
Warmbly
- Annual discount
20% off yearly billing
The pricing page shows a Save 20% toggle for yearly billing, for example Starter at $23 instead of $29 a month.
Warmup Inbox
- Annual discount
Save 20% with annual billing
Annual plans are billed once for 12 months: Basic is $15 per inbox a month billed annually against $19 billed monthly.
Common questions
Which is cheaper, Warmbly or Warmup Inbox?
As of Nov 13, 2026, Warmup Inbox is cheaper to start with: $15 a month, against $23 a month for Warmbly. Warmbly starts at $23 per month, billed yearly ($29 billed monthly), and Warmup Inbox starts at $15 per inbox / month, billed annually ($19 monthly).
Which has a free plan, Warmbly or Warmup Inbox?
As of Nov 13, 2026, neither Warmbly nor Warmup Inbox has a free plan. Both have a free trial.
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.