# Best AI Agents for Customer Support in 2026

> A verified comparison of Intercom Fin, Decagon, Sierra, Ada, Salesforce Agentforce, Zendesk AI Agents, and Gladly Sidekick, with real pricing and resolution-rate claims for autonomous customer support agents.

Published: 2026-08-20 · By: The AI Tools Desk

Customer support is the first place most companies actually let an AI agent touch a live customer relationship with money on the line, not a marketing draft or a code suggestion. That makes this category different from the generic AI agent tools we cover elsewhere on this site: the products here are judged on one number above all others, the share of tickets an agent closes without a human, and on how honestly that number is measured. We looked at nine vendors, verified pricing and resolution claims against official pricing pages, case studies, and recent funding disclosures, and kept the seven we could actually back up with sources. Two candidates we researched, Forethought and Crescendo, dropped out: Forethought is now a Zendesk-owned, quote-only add-on with no independent pricing to check, and Crescendo would not publish enough verifiable detail beyond a single third-party pricing estimate.

A note on resolution rates before the list: every vendor here markets a headline percentage, and those numbers are not directly comparable. Some count only fully autonomous closes, some count deflection (the customer left without escalating, which is not the same as being helped), and definitions of "resolved" vary by contract. Where we found a gap between a vendor's homepage number and an independently reported figure, we say so.

## [Intercom Fin](https://fin.ai/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list)

Fin is Intercom's AI agent, sold on outcome-based pricing at $0.99 per resolution, $0.99 per handoff or disqualification, and $9.99 per qualified lead, on any Intercom plan. Intercom's own site claims a 76% average resolution rate across more than 12,000 customers, with many above 85%. That is worth reading skeptically: individual published case studies land lower, Linktree at 42% and Robin at 50%, which suggests the average is pulled up by a long tail of simple, high-volume use cases. Fin is best for teams already running Intercom as their helpdesk, since it is not sold as a standalone product and setup leans on Intercom's existing knowledge base and macros.

## [Decagon](https://decagon.ai/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list)

Decagon builds omnichannel agents (voice, chat, email) from what it calls Agent Operating Procedures, natural-language workflow definitions rather than rigid decision trees, and it has become the reference enterprise vendor in this space: a $250 million Series D in January 2026 valued the company at $4.5 billion. There is no self-serve tier. The starting point is roughly a $50,000 annual platform fee plus usage, and reported median contracts run around $400,000 a year, so this is a tool for organizations with real budget and real ticket volume, not a team testing the waters. Customer-reported numbers are strong where public: Chime cites 70% chat and voice resolution, Duolingo cites an 80% deflection rate. Decagon is best for large, complex support operations (airlines, banks, telecom) that need one build to cover every channel and can absorb a multi-month sales and implementation cycle.

## [Sierra](https://sierra.ai/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list)

Sierra, co-founded by former Salesforce co-CEO Bret Taylor, is the fastest-growing name on this list by revenue: the company says it crossed $200 million in annual recurring revenue by May 2026, on the back of a $950 million Series C at a $15.8 billion valuation. Pricing is fully custom outcome-based (third-party trackers estimate roughly $1.50 per resolved interaction), and Taylor's public pitch is blunt, a human-handled service call costs a company $10 to $20 in labor, and Sierra charges a slice of what it saves. Enterprise deployments reportedly start around $200,000 to $350,000 in year one and can reach $750,000 to $1.5 million for multi-channel, multi-market rollouts. Sierra is best for large consumer brands (it counts Rocket Mortgage, SiriusXM, Gap, and Hyatt as customers) that want a fully managed, white-glove build rather than a self-service product; it is not aimed at smaller teams.

## [Ada](https://www.ada.cx/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list)

Ada calls itself an AI-native customer service platform for voice, messaging, and email, and it markets an automated resolution rate of up to 83 to 84%. Pricing is not public, but Vendr procurement data across 103 actual purchases puts the median annual contract near $70,000, with a rough starting shape of a $30,000 platform fee plus $1 to $3.50 per resolved interaction, rising past $300,000 a year for large enterprise deployments. One caution worth repeating: Ada's contracts reportedly define "resolution" differently account to account, so the 84% figure is not a like-for-like number you can compare against a competitor's claim. Ada is best for mid-market to enterprise teams (Pinterest, Grab, Sky, and Barnes & Noble are customers) that want faster time-to-value than Decagon or Sierra without going fully self-serve.

## [Salesforce Agentforce](https://www.salesforce.com/agentforce/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list)

Agentforce is Salesforce's agent layer for Service Cloud, and it is the one product here with fully public, official pricing: $2 per resolved conversation on the pay-per-conversation model, or Flex Credits at $500 per 100,000 credits, where a standard agent action costs 20 credits. A typical support conversation runs 8 to 15 actions, which works out to roughly $0.80 to $1.50 in effective credit cost, cheaper than the flat $2 rate at moderate complexity. The catch is that Agentforce needs Service Cloud running underneath it, third-party implementation estimates put total setup at $20,000 to $100,000 and 5 to 11 months to production, and per-user add-ons stack on top ($5 to $125 per user per month depending on tier). Agentforce is best for organizations already committed to Salesforce Service Cloud; it is a poor fit as a first support platform.

## [Zendesk AI Agents](https://www.zendesk.com/service/ai/ai-agents/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list)

Zendesk folded its AI agent into every Support and Suite plan ($19 to $115 per agent per month, annual billing) and bills automated resolutions separately, officially "you pay only for customer requests that were successfully resolved by the AI agent, without escalation." Zendesk markets 50 to 80% autonomous resolution. That is the widest gap we found between marketing and field reporting: independent 2026 analyses put real-world resolution closer to 10 to 20% without custom API work, meaning the AI often deflects rather than resolves. A January 2026 billing change also began auto-charging resolution overages above committed volume, on an uncapped meter, so costs can surprise teams that scale usage without renegotiating. Zendesk AI is best for teams already on Zendesk who want incremental automation, not a headline resolution rate.

## [Gladly](https://www.gladly.com/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) Sidekick

Gladly built its reputation on a single customer timeline instead of ticket threads, and its AI agent, Sidekick, claims a 76% autonomous resolution rate. It is also the only vendor here with a genuinely accessible small-business entry point: a free 30-day trial, then $1.50 per AI resolution, $0.25 per AI assist, and $120 per agent seat per month. Mid-market and enterprise pricing steps up to roughly $180 to $210 per agent per month with AI conversations billed separately around $0.60 each. Gladly is best for retail and DTC brands that want the AI agent and human agents working off the same customer record rather than bolted onto a legacy ticket queue.

## Comparison

| Tool | Pricing model | Reported resolution rate | Best for |
|---|---|---|---|
| Intercom Fin | $0.99/resolution, $9.99/qualified lead | 76% vendor average; 42-50% in individual case studies | Teams already on Intercom |
| Decagon | ~$50K/yr platform fee + usage | 70-80% (customer-reported) | Large, complex, multi-channel enterprises |
| Sierra | Custom outcome-based, ~$1.50/resolution (est.) | Not independently published | Consumer brands wanting a managed build |
| Ada | ~$30K/yr + $1-3.50/resolution (est.) | Up to 83-84% (vendor) | Mid-market to enterprise, faster rollout |
| Salesforce Agentforce | $2/conversation or Flex Credits ($500/100K) | Not independently published | Existing Salesforce Service Cloud shops |
| Zendesk AI Agents | $19-$115/agent/mo + pay-per-resolution | 50-80% vendor; ~10-20% field-reported | Teams already on Zendesk |
| Gladly Sidekick | $1.50/resolution + $0.25/assist + $120/seat | 76% (vendor) | Retail/DTC, unified customer timeline |

## How to choose

If you already run your helpdesk on Intercom, Zendesk, or Salesforce, start with that vendor's own agent (Fin, Zendesk AI, or Agentforce) before evaluating a standalone platform. It is the cheapest path to a working pilot and you already have the ticket data to train it. If you are an enterprise with high ticket volume, real budget (six figures a year, minimum), and complex, multi-channel workflows that a rules-based bot has already failed at, Decagon and Sierra are the two vendors built for that problem, and the choice between them mostly comes down to sales relationship and how much you want a fully managed build versus more hands-on control. If you want to test an AI-native agent without a six-month procurement cycle, Ada and Gladly's small-business tier are the most accessible entry points with usage-based pricing you can actually estimate in advance. Whatever you pick, insist on seeing resolution-rate methodology in writing before you sign, given how far vendor and field numbers diverged in our research.

## Verdict

For most teams that do not already have a large enterprise support operation, Intercom Fin is the pragmatic starting point: pricing is public, the per-outcome model means you are not paying for failed conversations, and it is bolted onto a helpdesk you can be running the same week. Enterprises with the budget and ticket volume to justify it should put Decagon and Sierra on a shortlist instead, since both are built and staffed for the kind of complex, high-stakes deployments that make a percentage point of resolution rate worth real money.

## Frequently asked questions

### What makes an AI customer support agent different from a chatbot?

A scripted chatbot follows a fixed decision tree and hands off anything outside it. The agents in this list are built to take actions (issuing refunds, updating orders, rebooking flights) and resolve a ticket end to end without a human, using account data and integrations rather than a fixed script. That distinction is also why pricing has shifted toward per-resolution or per-conversation billing instead of flat per-seat software fees.

### How much should I budget for an AI customer support agent?

It depends heavily on ticket volume and vendor. Self-serve entry points like Intercom Fin ($0.99 per resolution) or Gladly's small-business tier (from $120 per seat plus $1.50 per resolution) can start in the low thousands per month. Enterprise platforms like Decagon or Sierra typically involve six-figure annual contracts once platform fees and usage are combined, so get a volume-based quote before assuming a per-resolution price applies at your scale.

### Can I trust the resolution rate a vendor advertises?

Treat headline percentages as a starting point, not a guarantee. We found real gaps between vendor marketing and independently reported numbers, most notably Zendesk (50 to 80% marketed versus roughly 10 to 20% in field reports) and Intercom Fin (76% vendor average versus 42 to 50% in individual published case studies). Ask any vendor exactly how they define a resolution and whether that includes conversations the customer simply abandoned.

### Do these AI agents work with my existing helpdesk?

Vendor-native agents (Intercom Fin, Zendesk AI Agents, Salesforce Agentforce) are built into their own platform and are the easiest integration if you already run that helpdesk. Standalone platforms like Decagon, Sierra, Ada, and Gladly are designed to sit on top of or alongside an existing helpdesk and typically integrate with Zendesk, Salesforce, and similar systems, but confirm your specific stack during a sales evaluation since integration depth varies by connector.

## Sources

- [Fin AI Agent](https://fin.ai/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Intercom (Fin)
- [Sierra Platform](https://sierra.ai/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Sierra
- [Agentforce Pricing](https://www.salesforce.com/agentforce/pricing/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Salesforce
- [Decagon](https://decagon.ai/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Decagon
- [Ada](https://www.ada.cx/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Ada
- [Zendesk Pricing](https://www.zendesk.com/pricing/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Zendesk
- [Decagon revenue, valuation & funding](https://sacra.com/c/decagon/?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Sacra
- [How Does Sierra AI Make Money: Outcome-Based Pricing at a $15.8B Valuation](https://valueaddvc.com/blog/how-does-sierra-ai-make-money-outcome-based-pricing-enterprise-agents-and-the-business-model-breakdown?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Value Add VC
- [Gladly pricing in 2026: plans, AI costs, and real totals](https://www.eesel.ai/blog/gladly-pricing?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — eesel AI
- [Intercom Fin AI Pricing Explained: Evaluating $0.99 Per Resolution in 2026](https://www.gleap.io/blog/intercom-fin-ai-pricing-2026?utm_source=guides.reviews&utm_medium=referral&utm_campaign=best_list) — Gleap