Boom vs Sierra
Boom gives the agent your customer data, segments that start journeys, a shared inbox for your team, and reports built from every reply.
The main difference
An AI agent that reaches out from your own CDP, segments and journeys, and turns every reply into data.
A conversational AI platform for large brands, with agents priced by the outcomes they deliver.
Boom vs Sierra, side by side
Both run AI agents that start conversations. Here is where they differ, from Sierra’s own pages.
- Starts the conversation
BoomYes. The agent writes or calls first, when your journey says so
SierraYes. Horizon follows up across text, phone and email over days or weeks
- Holds a real two-way conversation
BoomYes. An AI agent reads every reply, asks the follow-up and acts on it
SierraYes, across chat, messaging, email and voice
- Channels
BoomWhatsApp, Instagram, Messenger, SMS, email, voice and web chat, with one memory
SierraChat, SMS, WhatsApp, email, voice and ChatGPT. Instagram and Messenger not listed
- Phone calls
BoomYes. The same agent calls, and a chat can turn into a call
SierraYes. Inbound and outbound calls, with payments taken during the call
- Customer data
BoomBuilt-in CDP that reads live from your database or API. No CSV
SierraCustomer history in its Context Engine, plus 40+ integrations
- Journeys
BoomVisual builder: send, wait, branch, change channel, call your API
SierraHorizon Playbooks act on signals toward an outcome
- Turns replies into data
BoomYes. Extraction fills typed fields and reports from every conversation
SierraInsights tags conversations, tracks CSAT and answers questions in plain language
- Human handoff
BoomShared inbox. A person takes over with the full context
SierraRoutes to your care team through your contact center tools
- Spanish and Portuguese
BoomNative. The agent, the product and the team work in es, pt and en
SierraVoice agents speak 55+ languages and switch mid-call
- Pricing
BoomPlans from USD 350 a month. Credits cover conversations, calls and messages
SierraOutcome-based, through sales. No public price list
What we say about Sierra comes from its own public pages, checked on October 15, 2026. Something changed? Tell us and we will fix it.
Which one should you choose?
Choose Boom if:
- You want customer data, segments and journeys in the same product as the agent.
- You want answers saved as typed fields and reports, not only tags and CSAT scores.
- You want a shared inbox where your team takes over, without wiring in contact center tools.
- You want published plans you can compare, not an outcome-based contract through sales.
Choose Sierra if:
- Voice is your main channel at contact center scale, with payments taken during the call.
- Your security review requires FedRAMP High or PCI DSS Level 1 today.
- You run a large consumer brand and want an enterprise contract priced by outcome.
- Your human reps want Live Assist suggesting replies while they help customers.
What comes with Boom
- 01
Connects to your database
Plug in a read-only database, Shopify, Skio or the events API. The agent reads live data, so there is never a CSV to upload.
- 02
An agent live in two days
Connect a channel, pick who to reach and review the first conversations. Your agent is talking to customers in two days.
- 03
Replies become data
Define the fields you want to learn. Boom fills them from every conversation and rolls them into a report you can export.
Boom vs Sierra, answered
Is Boom a Sierra alternative?
Yes. Boom runs AI agents that start and hold conversations on WhatsApp, voice, SMS, email, Instagram, Messenger and web chat, and brings its own CDP, journeys, shared inbox and extraction that turns replies into data.
Does Sierra reach out to customers too?
Yes. Sierra’s Horizon agents follow up across text, phone and email. The difference is what surrounds the agent: Boom brings the customer data, segments, journeys and inbox in one product.
How is pricing different?
Sierra prices by outcome, through a sales conversation. Boom publishes its plans on its pricing page, with credits that cover conversations, calls and messages.
How long does switching take?
Days. Connect your channels, pick who to reach first, and review the first conversations before going to full volume.
See the whole loop on Boom
Bring one outcome you want, like renewals or win-backs. We will build the segment, the journey and the report in Boom, and show you the conversations.