# Decagon vs Sierra

> Decagon vs Sierra: Decagon is our pick, leading for agencies and outbound sales. They split on languages supported and funding stage.

Both Voice AI platforms, Decagon (AI concierge platform - voice/chat/email agents driven by natural-language Agent Operating Procedures (AOPs).) and Sierra (Outcome-priced conversational AI agent platform from Bret Taylor and Clay Bavor; voice product replaces IVR with an empathetic agent.) go head to head here. Start with the bottom line, then the verified fact table and real production costs.

Voice AI platforms · 14 facts compared · all sourced

## Bottom line

Decagon takes 3 of 6 use cases against Sierra's 2, with 1 tie, and the wins are backed by meaningful capability advantages. For no-code agency deploys, Decagon offers a no-code agent builder that lowers the barrier for non-technical teams. For outbound sales campaigns, Decagon provides native outbound campaign support, a feature Sierra does not match. For SMB receptionist and booking, Decagon's 70 supported languages versus Sierra's 55 gives it a clear reach advantage for diverse customer bases. Sierra counters with a simulation and testing suite and outcome-based per-resolution pricing that suits ecommerce and custom pipelines, but those 2 wins fall short of Decagon's breadth. Decagon's $481M total funding also signals strong enterprise momentum.

## Verdict summary

| Use case | Winner | Why |
| --- | --- | --- |
| No-code agency deploys | Decagon | For a no-code agency deploying and reselling AI agents, the agent builder and outbound capabilities are critical. |
| Custom pipeline control | Sierra | For engineering teams building custom pipelines, iteration speed depends heavily on a simulation and testing suite. |
| Ecommerce support and orders | Sierra | For ecommerce support, native integrations and a built-in knowledge base are the deciding factors, but neither tool publishes details on either front. |
| Healthcare compliance | Tie | For HIPAA-bound healthcare workflows, the single most critical requirement is a HIPAA BAA, and both Decagon and Sierra include it on their base plans. |
| Outbound sales campaigns | Decagon | For outbound sales and call-center campaigns, the single most important capability is native outbound campaign support. |
| SMB receptionist and booking | Decagon | For an SMB receptionist and booking setup, the platform fee is the single most important factor, and neither tool publishes a specific monthly fee, so that attribute does not separate them. |

## Decagon vs Sierra: head-to-head facts

| Fact | Decagon | Sierra | Verified |
| --- | --- | --- | --- |
| HIPAA BAA on base plan | ✓  Included ([source](https://decagon.ai/security)) | ✓  Included ([source](https://sierra.ai)) | Jul 30 |

## Decagon vs Sierra pricing: true cost at 3 usage tiers

All-in monthly: platform fee + per-minute + telephony. Assumes GPT-4o class model, ElevenLabs voice.

| Volume | Buyer | Decagon | Sierra | Note |
| --- | --- | --- | --- | --- |
| 1K min/mo | Solo builder | n/a | n/a | Includes estimated telephony. Free credits can offset the first month. |
| 10K min/mo | Agency | n/a | n/a | Volume pricing typically starts to apply at this tier. |
| 100K min/mo | Call center | n/a | n/a | Both platforms offer custom contracts at this tier. Negotiate. |

## Decagon vs Sierra: verdicts by use case

### No-code agency deploys → Decagon

For a no-code agency deploying and reselling AI agents, the agent builder and outbound capabilities are critical. Decagon confirms a no-code agent builder and native outbound campaigns, giving agencies the tools to build and run client programs without engineering help. Sierra has no verified no-code builder or outbound campaigns. Both tools lack published white-label or sub-account details, so that attribute is a wash. Decagon also supports 70 languages versus Sierra's 55, broadening resale opportunity. The confirmed no-code builder plus native outbound campaigns tips the decision toward Decagon.

### Custom pipeline control → Sierra

For engineering teams building custom pipelines, iteration speed depends heavily on a simulation and testing suite. Sierra has a verified testing suite, while no such fact exists for Decagon. On the other four deciding factors, including bring-your-own LLM, API-first architecture, latency, bring-your-own voice, and SIP trunking, neither tool has published information, so these factors cannot separate them. Sierra's edge on the testing suite, the one factor with a clear data point, tips the decision. Both tools share HIPAA, SOC 2, GDPR, and warm transfer parity. Decagon supports 70 languages versus Sierra's 55, but language breadth is not relevant to custom pipeline control.

### Ecommerce support and orders → Sierra

For ecommerce support, native integrations and a built-in knowledge base are the deciding factors, but neither tool publishes details on either front. Where the two do differ: Sierra supports DTMF/IVR navigation while Decagon does not, which matters for order-status phone flows common in ecommerce. Decagon supports 70 languages versus Sierra's 55, though that is a smaller advantage for this use case. Both lack self-serve signup. Sierra's DTMF support gives it a concrete, ecommerce-relevant edge.

### Healthcare compliance → Tie

For HIPAA-bound healthcare workflows, the single most critical requirement is a HIPAA BAA, and both Decagon and Sierra include it on their base plans. Both are also SOC 2 Type II certified and offer GDPR tooling, covering the core compliance stack that healthcare buyers demand. Both support warm transfer to a human agent, which is essential when sensitive clinical conversations need escalation. Neither product reveals a consent or recording compliance tooling advantage, so that attribute cannot differentiate them. With every published compliance credential matching precisely, there is no fact-grounded basis to prefer one over the other for this use case.

### Outbound sales campaigns → Decagon

For outbound sales and call-center campaigns, the single most important capability is native outbound campaign support. Decagon explicitly has it while Sierra does not, and that gap alone is decisive for this use case. Both platforms support warm transfer to a human agent, so they are equal on that secondary factor. Concurrency limits and SIP trunking details are unavailable for either platform, so those factors cannot differentiate the two. Decagon also supports 70 languages versus Sierra's 55, giving it broader reach for multilingual outbound campaigns.

### SMB receptionist and booking → Decagon

For an SMB receptionist and booking setup, the platform fee is the single most important factor, and neither tool publishes a specific monthly fee, so that attribute does not separate them. On the no-code agent builder, Decagon is confirmed to offer one while no equivalent fact exists for Sierra, giving Decagon a concrete edge for a small business owner who needs to configure and adjust an agent without developer help. Both tools support warm transfer to human, which is essential for after-hours handoffs and reception coverage. Decagon also supports 70 languages versus Sierra's 55, adding flexibility for diverse customer bases. With Decagon confirmed on the no-code builder and matching Sierra on every shared compliance and call-handling feature, it edges ahead for this use case.

## Decagon vs Sierra: common questions

### Is Decagon cheaper than Sierra?

Neither Decagon nor Sierra publishes standard list pricing publicly. Sierra uses outcome-based pricing, meaning you pay per resolved conversation. Decagon's pricing is also available only through a sales conversation. Because no comparable base prices are disclosed for either platform, it is not possible to determine which is cheaper without requesting a custom quote from each vendor directly.

### Decagon vs Sierra: which is better for no-code agency deploys?

Decagon explicitly offers a no-code agent builder, making it the stronger pick if your team wants to build and deploy agents without writing code. Sierra does not have a confirmed no-code builder. Both platforms require a sales conversation to get started, so neither offers instant self-serve access. Decagon also supports native outbound campaigns, which can expand what a no-code deployment can do.

### Does Decagon or Sierra support more languages for multilingual customer service?

Decagon supports 70 languages while Sierra supports 55, giving Decagon broader multilingual coverage. If your customer base spans many regions or less common languages, Decagon has a clear edge in raw language count.

### Is Decagon or Sierra better for running outbound call campaigns?

Decagon natively supports outbound campaigns. No equivalent capability is confirmed for Sierra, so buyers who need proactive outreach built into their AI voice platform should weigh Decagon more heavily for that use case.

### Do Decagon and Sierra both include a HIPAA BAA for healthcare use cases?

Both Decagon and Sierra include a HIPAA Business Associate Agreement on their base plans, making either a viable starting point for healthcare-adjacent deployments that require HIPAA compliance.

### Is Decagon or Sierra a better alternative for teams that need DTMF or IVR navigation support?

Sierra explicitly supports DTMF/IVR navigation. Decagon does not confirm this feature, making Sierra the safer choice for deployments that must integrate with traditional phone trees or legacy IVR systems.

### Can I sign up and start using Sierra or Decagon without talking to sales?

Neither Sierra nor Decagon offers a self-serve signup. Both require you to go through a sales or onboarding process before gaining access, so plan for some lead time regardless of which platform you choose.

### How does Sierra price its AI agent platform?

Sierra uses outcome-based pricing, meaning you pay per resolution rather than a flat monthly seat fee. This model ties costs directly to successful customer interactions, which can be advantageous or unpredictable depending on your resolution volume.

### Does Sierra include a simulation or testing suite for validating agents before going live?

Sierra includes a simulation and testing suite, allowing teams to validate agent behavior before deployment. This is useful for quality assurance in complex or high-stakes customer service workflows.

### How well-funded are Decagon and Sierra, and are they established companies?

Both companies were founded in 2023 and are headquartered in San Francisco. Decagon has raised $481M total, reaching a $4.5B valuation at Series D. Sierra raised a $350M round at a $10B valuation in September 2025, backed by Greenoaks. Both are well-capitalized by late-stage standards.

Source: https://www.versusref.com/voice-ai/decagon-vs-sierra/