ONES vs Slack: Complete Comparison (2026)
An in-depth comparison of ONES and Slack to help you choose the right tool for your business.
Last updated: November 2026
ONES
6.5/10
ONES is a project management and software delivery platform for engineering and product teams, combining issue tracking, sprints, test management, and a wiki.
Slack
7.1/10
Slack is a channel-based messaging platform from Salesforce, with Lists, canvases, huddles and Workflow Builder for team coordination and light task tracking.
Feature-by-Feature Comparison
| Feature | | |
|---|---|---|
| Scores | ||
| Overall Rating | 6.5/10 | 7.1/10 |
| Analytics | 6/10 | 3/10 |
| Cost | 7/10 | 5/10 |
| Customization | 7/10 | 7/10 |
| Ease of Use | 6/10 | 7/10 |
| Integration | 5/10 | 10/10 |
| Scalability | 7/10 | 9/10 |
| Security | 8/10 | 9/10 |
| Support | 7/10 | 6/10 |
| Pricing | ||
| Free plan | Yes | Yes |
| Cheapest paid plan | $99/user/mo Standard | €8/user/mo Pro |
| Estimated cost for 10 users | Free Free | Free Free |
| Features | ||
| Gantt charts | ||
| App integrations | ||
| Collaboration tools | ||
| Docs | ||
| Kanban boards | ||
| Spreadsheet interface | ||
| Task lists | ||
| Task management | ||
| Workflow automation | ||
| Client collaboration | Not listed | |
| Dashboards | Not listed | |
| File sharing | Not listed | |
| Knowledge base | Not listed | |
| Reporting | Not listed | |
| Scheduling | Not listed | |
| Team messaging | Not listed | |
| Time tracking | Not listed | |
| Timeline view | Not listed | |
ONES vs Slack cost by team size
| Team size | ONES | Slack |
|---|---|---|
| 1 user | FreeFree | FreeFree |
| 5 users | FreeFree | FreeFree |
| 10 users | FreeFree | FreeFree |
| 25 users | FreeFree | FreeFree |
| 50 users | $8,600/moBusiness | FreeFree |
The plan that fits each team size, billed monthly, before add-ons and usage charges. Each cost opens that tool's pricing calculator for the team size.
Which One Should You Choose?
Why choose ONES
- Higher Analytics score (6/10 vs 3/10)
- Higher Cost score (7/10 vs 5/10)
- Better fit for developers (9/10 vs 7/10)
- Includes Gantt charts, which Slack lacks
Why choose Slack
- Higher Integration score (10/10 vs 5/10)
- Higher Scalability score (9/10 vs 7/10)
- Better fit for agencies (7/10 vs 3/10)
- Better fit for small business (8/10 vs 5/10)
Pros & Cons
ONES
Pros
- The free plan covers up to 30 seats and already includes sprint, test, and release management.
- Issue tracking, test cases, and the wiki live in one product, so teams do not have to link Jira, a test tool, and Confluence.
- It can be deployed as SaaS, on-premises, in a private cloud, or air-gapped, which suits regulated industries.
- The vendor reports SOC 2 Type II, ISO 27001, ISO 27018, and GDPR compliance.
- Business and Enterprise plans include tooling to migrate from Jira and Confluence.
Cons
- There are very few independent reviews: about 13 on G2 and 9 on Capterra.
- G2 reviewers mention a learning curve for new users.
- Its third-party integration catalogue looks small next to Jira's or monday.com's.
- Gantt charts and automation need a paid plan, and resource scheduling needs Business.
- Most of the comparison content available online is published by ONES itself.
Slack
Pros
- The app ecosystem is very large, and tools such as ClickUp, Notion, HubSpot and Clockify can post updates into channels.
- Slack Connect lets teams work in shared channels with up to 250 outside organizations on paid plans.
- Compliance coverage is broad, including ISO 27001, SOC 2 Type II, FedRAMP Moderate and HIPAA configurability.
- Lists add table and board layouts with assignees, due dates and subtasks, without leaving chat.
- Workflow Builder automates routine requests and approvals without code.
Cons
- There are no native Gantt charts, dependencies, time tracking or portfolio reporting, so Slack doesn't replace a dedicated PM tool.
- Frequent notifications and busy channels can interrupt focus, a common complaint in reviews.
- The free plan keeps only 90 days of message history and allows 10 apps.
- Advanced AI features require Business+ or above, and per-user costs add up as teams grow.
- Reviewers report that finding older messages through search can be difficult.
Not sold on either?
Frequently Asked Questions
Slack scores higher on our Project Management criteria: 7.1/10 against 6.5/10 for ONES. The largest gap is in Integration: 5/10 for ONES and 10/10 for Slack.
Yes, both ONES and Slack have a free plan.
Slack is the better fit for agencies: we rate it 7/10 for them, against 3/10 for ONES.
ONES has Gantt charts, which Slack lacks.
