# Assistly vs Sierra

> Assistly: AI chat assistant that answers website visitors and captures leads around the clock
> Sierra: Enterprise AI agents that handle customer conversations across voice, chat and messaging, priced by outcome

- Assistly profile: https://finderatlas.com/tools/assistly
- Sierra profile: https://finderatlas.com/tools/sierra
- Comparison page: https://finderatlas.com/compare/assistly-vs-sierra
- Last reviewed: October 2026

## Verdict

Assistly is listed under Live Chat Tools and Sierra under AI Customer Support. Only Assistly has a free plan or trial. Only Assistly offers an API.

### Choose Assistly if

- You want a tool built for answering common visitor questions after hours.
- Permanent free plan with 50 chats a month and no card required.
- Setup is one line of code, with guides for the main website builders.

### Choose Sierra if

- You want a tool built for large companies automating high-volume customer conversations across voice and digital channels with outcome-based pricing.
- Outcome-based pricing ties cost to results rather than seats or tokens.
- Covers voice, chat, SMS, WhatsApp, email and ChatGPT from one agent build.

## Pricing

| | Assistly | Sierra |
| --- | --- | --- |
| Pricing model | Freemium | Paid |
| Free plan or trial | Yes | No |
| Starting price | $0 | Custom |

## Features

| Feature | Assistly | Sierra |
| --- | --- | --- |
| Answers from your own content | Yes | Not listed |
| Multilingual replies | Yes | Not listed |
| Lead capture and alerts | Yes | Not listed |
| Human takeover | Yes | Not listed |
| Shared inbox | Yes | Not listed |
| WhatsApp answering | Yes | Not listed |
| Booking in chat | Yes | Not listed |
| One-line install | Yes | Not listed |
| Signed in users and AI actions | Yes | Not listed |
| REST API | Yes | Not listed |
| Agent Studio | Not listed | Yes |
| Ghostwriter | Not listed | Yes |
| Voice agents | Not listed | Yes |
| Multi-channel deployment | Not listed | Yes |
| Horizon | Not listed | Yes |
| Context Engine | Not listed | Yes |
| Insights and Explorer | Not listed | Yes |
| Experiments | Not listed | Yes |
| Knowledge management | Not listed | Yes |
| Trust and reliability | Not listed | Yes |

## Platforms

| Platform | Assistly | Sierra |
| --- | --- | --- |
| Web | Yes | Yes |
| Windows | No | No |
| macOS | No | No |
| iOS | No | No |
| Android | No | No |
| API | Yes | No |
| Browser Extension | No | No |

## Assistly strengths

- Permanent free plan with 50 chats a month and no card required.
- Setup is one line of code, with guides for the main website builders.
- Answers in the visitor's language and trains on pages and uploaded files.
- Human takeover, lead status tracking and email or phone alerts are on every plan.
- Plain trust page covering hosting, encryption, two step sign in and data deletion.

## Assistly limitations

- Very new product (domain registered April 2026), with no public customer count or independent reviews found.
- Paid billing is not open yet, so paid plan prices may still change.
- Web only: no native mobile app or browser extension.
- WhatsApp on the Free plan and each extra integration beyond the plan limit cost $19.99 a month; extra team members cost $19 a month.
- Replies depend on OpenAI models, so chat content is sent to a third party.

## Sierra strengths

- Outcome-based pricing ties cost to results rather than seats or tokens.
- Covers voice, chat, SMS, WhatsApp, email and ChatGPT from one agent build.
- Ghostwriter can create agents from existing SOPs, transcripts or audio interviews.
- Large enterprise customer base named on the homepage, including Uber, Vanguard and Hyatt.
- Broad compliance list, including SOC 2, ISO 42001, HIPAA and FedRAMP.
- Built-in analytics, monitors and experiments for tuning agent behavior.

## Sierra limitations

- No published pricing and no self-serve signup or free trial found.
- Aimed at enterprises; small businesses are not the evident target.
- Outcome-based billing can make monthly cost harder to forecast.
- Public documentation for developers (API or SDK) was not found on the official site.

## FAQ

**Is Assistly better than Sierra?**

It depends on your workflow. Assistly is built for answering common visitor questions after hours. Sierra is built for large companies automating high-volume customer conversations across voice and digital channels with outcome-based pricing.

**What are the key feature differences between Assistly and Sierra?**

Assistly: AI chat assistant that answers website visitors and captures leads around the clock. Sierra: Enterprise AI agents that handle customer conversations across voice, chat and messaging, priced by outcome.

**Does Assistly or Sierra have a free plan?**

Assistly has a free plan or trial; Sierra is paid only.

**Which is cheaper, Assistly or Sierra?**

Assistly starts at $0 and Sierra starts at Custom. See the pricing table above for what each tier includes.