# Decagon vs Plain

> Decagon: Enterprise AI agents that resolve customer conversations across chat, email and voice
> Plain: AI-powered support platform for B2B teams, unifying Slack, email and chat in one workspace

- Decagon profile: https://finderatlas.com/tools/decagon
- Plain profile: https://finderatlas.com/tools/plain
- Comparison page: https://finderatlas.com/compare/decagon-vs-plain
- Last reviewed: November 2026

## Verdict

Decagon is listed under AI Customer Support and Plain under Help Desk Software. Plain scores higher in FinderAtlas's editorial review (7.9 vs 7.6 out of 10), led by ease of use and value for money. Neither has a free plan. Only Plain offers an API.

### Choose Decagon if

- You want a tool built for large companies with high conversation volume that want AI agents handling chat, email and voice with testing and QA built in.
- Covers voice, chat and email in one platform rather than chat only.
- Natural-language AOPs let non-engineers define agent workflows.

### Choose Plain if

- You want a tool built for Teams that support business customers through shared Slack or Teams channels and want AI triage, routing and an API-first setup.
- Built around B2B support, with Slack, Teams and Discord channels alongside email and chat.
- Ari and Sidekick AI agents are included from the entry plan.

## Pricing

| | Decagon | Plain |
| --- | --- | --- |
| Pricing model | Paid | Free trial |
| Free plan or trial | No | No |
| Starting price | Custom | $45 |

## Features

| Feature | Decagon | Plain |
| --- | --- | --- |
| Agent Operating Procedures (AOPs) | Yes | Not listed |
| Voice, Chat and Email Agents | Yes | Not listed |
| Pre-built Integrations | Yes | Not listed |
| Experiments | Yes | Not listed |
| Testing & QA | Yes | Not listed |
| Watchtower | Yes | Not listed |
| Insights & Reporting | Yes | Not listed |
| Suggestions | Yes | Not listed |
| Duet | Yes | Not listed |
| Personal Agent Detection | Yes | Not listed |
| Multichannel Inbox | Not listed | Yes |
| Ari AI Agent | Not listed | Yes |
| Sidekick | Not listed | Yes |
| Workflows | Not listed | Yes |
| Insights | Not listed | Yes |
| Bring Your Own Agents | Not listed | Yes |
| API | Limited | Yes |
| Help Center and Knowledge Base | Not listed | Yes |

## Platforms

| Platform | Decagon | Plain |
| --- | --- | --- |
| Web | Yes | Yes |
| Windows | No | No |
| macOS | No | No |
| iOS | No | No |
| Android | No | No |
| API | No | Yes |
| Browser Extension | No | No |

## Decagon strengths

- Covers voice, chat and email in one platform rather than chat only.
- Natural-language AOPs let non-engineers define agent workflows.
- Built-in A/B experiments, simulations and always-on QA support ongoing tuning.
- Large enterprise customer list including airlines, telecoms and fintech companies.
- Offers a per-resolution pricing option where escalations are not charged.

## Decagon limitations

- No published pricing; every deal requires a sales conversation.
- No free tier or trial advertised, which limits evaluation by small teams.
- Reviewers have noted limited transparency into why the AI made a given decision.
- No public API or developer documentation was found on the official site.

## Plain strengths

- Built around B2B support, with Slack, Teams and Discord channels alongside email and chat.
- Ari and Sidekick AI agents are included from the entry plan.
- API-first design allows custom workflows and embedding.
- 7-day trial without a credit card, plus a 50% startup discount.
- Enterprise options include SSO, SCIM and HIPAA on the Frontier plan.

## Plain limitations

- No permanently free plan; paid plans start at $45 per user per month.
- AI usage is metered in credits (1,000 per month on Foundation), which makes costs harder to predict.
- Microsoft Teams and CRM integrations require the $99 Horizon plan.
- No iOS or Android app was found.

## FAQ

**Is Decagon better than Plain?**

It depends on your workflow. Decagon is built for large companies with high conversation volume that want AI agents handling chat, email and voice with testing and QA built in. Plain is built for Teams that support business customers through shared Slack or Teams channels and want AI triage, routing and an API-first setup.

**What are the key feature differences between Decagon and Plain?**

Decagon: Enterprise AI agents that resolve customer conversations across chat, email and voice. Plain: AI-powered support platform for B2B teams, unifying Slack, email and chat in one workspace.

**Does Decagon or Plain have a free plan?**

Neither has a free plan. Both Decagon and Plain are paid products.

**Which is cheaper, Decagon or Plain?**

Decagon starts at Custom and Plain starts at $45. See the pricing table above for what each tier includes.