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Side-by-side comparison · Sales & Customer Support

Intercom vs Retell AI vs Sierra

Everything that matters when choosing between them, in one place: our rating, what each can do, what they cost, and the trade-offs.

Best overall

Intercom

4.2

From $0.99 per outcome

Retell AI

4.1

From About $0.07–$0.31/min

Sierra

3.9

Free to start

Comparing 3 tools, the maximum.

At a glance

Best overallEasiest to use

Pick it if: Online businesses and software companies with a support team that wants an AI agent to take the first pass at every question.

Best value

Pick it if: Service businesses and agencies that want an AI receptionist or phone agent without hiring developers.

Pick it if: Large consumer brands that want an AI agent to handle a big share of their customer conversations end to end.

Intercom scores highest overall, but Retell AI gives you more for your money. Which one is right comes down to what you value most.

Overview

AttributeIntercomRetell AISierra
In one lineCustomer support inbox, help centre and chat, with the Fin AI agent answering first.AI phone agents that answer calls, book appointments and make outbound calls.Builds and runs AI customer service agents for big brands, across chat, email and phone.
Pricing modelPaidPaidPaid
Starting price$0.99 per outcomeAbout $0.07–$0.31/minSee website
Free plan No No No
Works with Claude Code Yes Yes No

Rating breakdown

Our scores out of 5. The higher bar in each row is highlighted.

AttributeIntercomRetell AISierra
Overall rating4.2Winner4.13.9
Ease of useHow quickly someone non-technical gets value from it.
4.0
3.5
3.0
FeaturesHow completely it covers its own job, and how well the pieces fit together.
5.0
4.5
4.5
Output qualityHow good the results are before you fix them.
4.5
4.5
4.5
Value for moneyWhat you get for the price, including the free plan.
3.0
4.0
3.0
Speed & reliabilityHow fast it is and how often it falls over.
4.5
4.0
4.5

Feature comparison

A tick means it does this today. A dash means we haven't checked.

AttributeIntercomRetell AISierra
Access & platform
Free plan No No No
Mobile app Yes––
Desktop app–––
Browser extension–––
API access Yes Yes–
Teams & business
Team workspace Yes Yes Yes
Enterprise plan or SSO Yes Yes Yes
Connects to other apps Yes Yes Yes
Open source or self-hosted No No No
AI abilities
Works with your files Yes Yes Yes
Understands images Yes––
Makes images No No No
Makes video No No No
Writes code No––
Runs agents or automations Yes Yes Yes
Learns your brand or style Yes– Yes
Works in many languages Yes Yes Yes
Capabilities score10/ 177/ 177/ 17

Pricing

Plans as listed on each vendor's site when we last checked. Confirm before you buy.

AttributeIntercomRetell AISierra
Plans

Fin on its own

$0.99 per outcome, monthly minimum

Teams happy with their current helpdesk who want the AI agent only.

Pay as you goOur pick

About $0.07–$0.31/min

Most small businesses and agencies.

EnterpriseOur pick

Custom

Large companies with high conversation volumes.

Essential

$29/seat/mo, plus $0.99 per Fin outcome

Small teams starting out with live chat and an AI agent.

Enterprise

Custom

High call volumes and compliance needs.

AdvancedOur pick

$85/seat/mo, plus $0.99 per Fin outcome

Growing support teams that need automation and several inboxes.

Expert

$132/seat/mo, plus $0.99 per Fin outcome

Larger teams with security and multi-brand needs.

Which plan to pickStart the 14-day trial and see how many conversations Fin handles, because that number drives the bill more than seats do. Most teams with more than a couple of agents end up on Advanced for the workflows. If you already run Zendesk or Salesforce and like it, try Fin on its own first.Start on pay as you go with the free credits, build one agent for your most common call and test it on your own phone. Talk to sales only once you run thousands of minutes a month.There is one route: talk to Sierra's sales team. Agree clearly what counts as an outcome you pay for, and what setup and services cost, before you sign.

Key features

AttributeIntercomRetell AISierra
Standout features
  • Fin AI agent
  • Shared inbox and tickets
  • Messenger chat widget
  • Help centre
  • Workflows
  • Copilot for agents
  • Phone agents
  • Flow builder
  • Appointment booking
  • Knowledge base
  • Batch calling
  • Call analysis
  • Agent Studio
  • Ghostwriter
  • One agent, every channel
  • Connected to your systems
  • Insights and testing

Pros and cons

AttributeIntercomRetell AISierra
Pros
  • Fin gives some of the most accurate answers of any AI support agent
  • Inbox, chat, help centre and AI all built to work together
  • Fin can run on top of another helpdesk, so you can trial it without moving
  • Clean, modern inbox that support staff pick up quickly
  • Public API and an official MCP server
  • Natural voices and quick responses
  • Visual builder makes it usable for non-developers
  • Pay per minute with no platform fee
  • Strong reviews from small businesses and agencies
  • Agents take real actions, not just answer questions
  • Covers voice as well as chat, SMS, WhatsApp and email
  • Outcome-based pricing means you pay for results, not seats
  • Proven at very large brands
Cons
  • Per-seat plus per-conversation pricing makes the monthly bill hard to predict
  • You pay for a Fin outcome even when a customer leaves after a weak answer, by some users' accounts
  • Many useful features sit on higher plans or paid add-ons
  • Slow or patchy responses from Intercom's own support in user reviews
  • Ownership change (renamed Fin, being bought by Salesforce) adds uncertainty
  • Per-minute cost varies a lot with your model and voice choices
  • Takes testing to handle real callers reliably
  • Some users want more voice and customisation options
  • No public pricing; estimates put it out of reach for most small and mid-sized businesses
  • No trial or self-serve option, so you are committing to a sales process and a project
  • Few independent reviews to check claims against
  • You depend on Sierra's team for much of the build

Who each one is for

AttributeIntercomRetell AISierra
Best for
  • Answering common customer questions automatically
  • Website and in-app live chat
  • A shared support inbox with ticketing
  • Building a help centre the AI learns from
  • Support across chat, email and phone in one place
  • AI receptionist for a small business
  • Booking appointments by phone
  • Answering after-hours and overflow calls
  • Outbound reminder and follow-up calls
  • High-volume customer service at large brands
  • AI phone agents that take real actions
  • Returns, bookings and account changes
  • Saving cancellations and handling retention calls
You'll find it used by
  • Support teams
  • Software companies
  • Online stores
  • Customer success teams
  • Small business owners
  • Clinics
  • Voice AI agencies
  • Customer service teams
  • Developers
  • Enterprise support teams
  • Contact centres
  • Retail brands
  • Banks and insurers
  • Telcos

Questions people ask

Which is better, Intercom, Retell AI or Sierra?

Intercom scores highest overall in our ratings (Intercom 4.2/5, Retell AI 4.1/5 and Sierra 3.9/5). Intercom is best for answering common customer questions automatically and website and in-app live chat. Retell AI is best for AI receptionist for a small business and booking appointments by phone. Sierra is best for high-volume customer service at large brands and AI phone agents that take real actions.

Which is cheaper, Intercom, Retell AI or Sierra?

Intercom: There's no free plan. Paid plans start at $0.99 per outcome. Retell AI: There's no free plan. Paid plans start at About $0.07–$0.31/min. Sierra: Pricing isn't published; check the vendor's site for a quote.

Which is easier to use, Intercom, Retell AI or Sierra?

Intercom rates highest for ease of use in our scores. Online businesses and software companies with a support team that wants an AI agent to take the first pass at every question.

How we compare

Ratings are our own, from using each tool, across ease of use, features, output quality, value for money, speed & reliability.

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