Pagerless makes this page, and lists itself first. Every other vendor's facts come from their own pages, linked below.
At a glance
| Tool | Free plan | Lowest paid | Phone and SMS |
|---|---|---|---|
| Pagerless | You + 1 backup, 3 apps, no card | Team planned: per alert sent, no per-seat price (not open yet) | Phone calls through your own Twilio at Twilio's price; no SMS |
| PagerDuty | Up to 5 users, 1 on-call schedule, 1 escalation policy, 3 months of history | Professional: $21 per user per month billed annually, $25 monthly | Free: 100 SMS or phone notifications a month. Professional: included, no monthly cap stated |
| incident.io | Basic: free, with 1 schedule, single-team on-call, 2 integrations and 1 status page | Team: $15 per user per month billed annually, plus $10 per user for on-call | Push, phone, SMS, email, Slack and WhatsApp paging; free-plan limits not stated |
| Better Stack | 10 monitors and heartbeats, 1 status page, Slack and email alerts | Responder license: $29 a month billed yearly, $34 monthly | Unlimited phone and SMS on paid responder licenses; not listed on the free tier |
| Rootly | No free plan; a trial, and a startup program with discounts | On-Call: $20 per user per month (billing basis not stated) | Push, phone, SMS, email, Slack and Teams; per-plan limits not stated |
| FireHydrant | Up to 10 responders and 2 runbooks; Signals on-call is listed on Pro and above | Pro: $25 per responder per month billed annually | SMS and voice available for purchase on Pro; prices not listed |
| Grafana OnCall | Grafana Cloud Free: IRM limited to 3 active users a month | Pro: $19 a month platform fee including 3 active IRM users, then from $20 per active user | IRM: no extra cost for outgoing calls or SMS; whether the free tier includes them is not stated |
1. Pagerless
Best for one person or a small team running an app, often built with AI. It wakes you only for what matters (four floors always do), explains what broke, and undoes a bad deploy with one tap on 20+ hosts. No schedules or rotations yet.
2. PagerDuty
An incident management and on-call platform with schedules, escalation policies and phone, SMS and push paging, plus a larger reliability platform sold in annual packages. Best for engineering and operations teams, from small teams to large enterprises.
3. incident.io
A Slack- and Teams-native incident response platform with an on-call product (schedules, escalations, mobile app, phone and SMS paging) and status pages. Best for software teams from startups to enterprises.
4. Better Stack
An observability suite with uptime monitoring, heartbeats, status pages, on-call scheduling and logs. Best for developers and small-to-mid engineering teams.
5. Rootly
A Slack-native incident response and on-call platform, sold as separate per-user products. Best for engineering and SRE teams at startups to enterprises.
6. FireHydrant
An incident management and reliability platform with Signals for on-call; Freshworks closed its acquisition of FireHydrant in January 2026. Best for engineering and SRE teams, with an enterprise focus. Acquired by Freshworks (agreement December 15, 2025; closed January 5, 2026).
7. Grafana OnCall
Grafana's on-call tool. The open-source edition was archived on March 24, 2026, and its cloud phone, SMS and push stopped; Grafana Cloud IRM is the hosted successor. Best for teams already on Grafana or Grafana Cloud. OnCall OSS: maintenance mode from March 11, 2025, archived March 24, 2026.
Moving from Zenduty
Step 1
Run
npx pagerless connect.Step 2
Move each integration's alerts.
Step 3
Set the escalation order.
Questions
What is the best free Zenduty alternative?
For a solo developer or a pair, Pagerless is free for you and one backup with up to 3 apps, and phone calls cost only Twilio's price on your own account. For bigger teams that need free schedules, compare the free plans in the table above.
Which Zenduty alternative has phone calls?
Most on-call tools do. Pagerless calls through your own Twilio account; the table shows each vendor's phone and SMS terms from their pricing page.