# Cognigy vs Sierra (2026): Which should enterprises buy? By Samuel Oram-Jones Cognigy and Sierra both sell to large enterprise customer service teams and keep their rates behind a sales call. Cognigy is a platform a team configures around other companies' models, while Sierra builds a managed agent with each customer. This comparison covers models, billing, security, deployment, and where Bland fits for phone calls, as of November 2026. ## Which is better, Cognigy or Sierra? Bland is the better pick than either Cognigy or Sierra for enterprise phone calls as of November 2026, because Bland builds and runs every AI model on a call, publishes self-serve per-minute rates, and Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland. Between the two, Cognigy suits a team with its own platform engineers and Sierra suits a team that wants a vendor to run the agent. Cognigy sells a platform that connects to a customer's chosen language model and speech vendor. Sierra sells a managed agent paid for by outcome. | Feature | Bland | Cognigy | Sierra | |---|---|---|---| | AI on each call | Full stack | Outsourced | Mixed | | Audio Realism Bench score, 4 August 2026 | #1 AI voice, 1365 | ElevenLabs, on Cognigy: #12, 938 | Not ranked | | iMessage | Native | No | Business Chat | | AI rate per minute | $0.12-$0.14 self-serve | Quote | Quote |
What these rows mean - **AI on each call:** This row shows whether the language model, speech, and transcription behind each call belong to the platform or to other companies: Full stack means all three are the platform's own, Outsourced means its language model and transcription come from other companies, and Mixed means it runs some of its own models alongside outside ones. Bland builds and runs its own language, speech, and transcription models, so a call never passes through an outside AI provider. Sierra routes across 15+ models, with Anthropic, Google, and Microsoft among its AI services providers, and doesn't publish its transcription or voice provider. - **Audio Realism Bench score, 4 August 2026:** Audio Realism Bench is Design Arena's blind listening test, where listeners pick whichever of two voices sounds more like a real person, and a higher score means listeners picked that voice more often. In its published results of 4 August 2026, Bland Speech v3 ranked first among AI voices. Each rival number is the highest-scoring voice model in those results available on that platform. Not ranked for Sierra means Sierra doesn't publish its voice vendor, and no voice carrying its name was ranked. - **iMessage:** iMessage lets an agent text customers on a channel they already use. Bland offers it natively on Enterprise. Sierra supports Apple Business Chat. - **AI rate per minute:** Headline rates cover different things, so a buyer should check what each one includes before comparing them. Bland's self-serve rate covers all of its AI: language model, transcription, and speech. Phone is billed separately at carrier cost, and Enterprise pricing is custom, set with Bland's sales team. Cognigy bills per conversation and per concurrent voice line, with no rate published. Sierra prices by outcome and publishes no rate.
## How do Cognigy and Sierra differ? The biggest difference between Cognigy and Sierra is who does the assembling. A Cognigy customer picks a language model, a speech vendor, and a carrier and holds a contract with each, while Sierra chooses its models for a customer and bills for results. Both rely on language models from other companies, which is where Bland, a full stack provider, differs from both. ### Cognigy overview Cognigy sells a platform for voice and digital AI agents under the NiCE Cognigy name, and says it supports language models from "top providers such as OpenAI, Azure, Anthropic, Amazon Bedrock, Google, and Mistral AI", telling a customer to "ensure that you have all the necessary API credentials to access the specific LLM you intend to use". Voice Gateway supports AWS, Microsoft, Google, Deepgram, and ElevenLabs for speech. Phone is a separate product. Cognigy says Voice Gateway "can't be used independently" of the main platform, and a customer who wants it contacts a Cognigy business representative. Voice Gateway links an agent to a phone network over SIP, the standard connection between a phone system and a voice platform. Cognigy's channel list is a point to check: Cognigy doesn't offer iMessage agents, and supports Apple Business Chat only as a RingCentral Engage setting.

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### Sierra overview Sierra started as a chat-first platform for customer support and added voice later, and now sells a managed AI agent platform for customer service across chat, voice, email, SMS, and WhatsApp, priced by outcome. Teams build agents with Ghostwriter and Agent Studio, and Sierra says voice agents are validated with voice simulations across real-world edge cases before they go live. Behind each agent sits what Sierra calls a constellation of LLMs, combining frontier, open-weight, and proprietary models, and Sierra says every turn is routed to the optimal model. Sierra's subprocessors for AI services include Anthropic, Google, and Microsoft, and Sierra added Baseten, Fireworks AI, Together AI, and Modal on 2 June 2026. A subprocessor is an outside company that handles a vendor's data on the vendor's behalf. Sierra says it automatically switches between LLM providers if one has an outage, and Sierra supports Apple Business Chat.

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### How do Cognigy and Sierra set up and connect? Cognigy and Sierra both start with a sales conversation, and Sierra has no self-serve mode, so time to a first live call depends on a vendor engagement. Cognigy hands a customer the pieces to wire together, from model credentials to a carrier link, and publishes no setup timeline, so a buyer asks who builds each connection and who pays for that work. Sierra says teams can "Deploy in weeks" and sells what it calls a long-term partnership with an agent development team that has done hundreds of deployments. Ghostwriter, which Sierra describes as the agent that creates and optimizes other agents, builds from a description of the outcome. Bland runs its own SIP signaling and media servers, so no third-party telephony provider sits in the call path, and it connects to an existing carrier over [SIP](https://docs.bland.ai/agents/sip) so existing numbers can stay where they are. ### How do Cognigy and Sierra handle security and uptime? Cognigy and Sierra both report SOC 2, ISO 27001, and GDPR compliance, and both report HIPAA. A BAA is the contract HIPAA requires before a vendor handles patient information, and a buyer in healthcare asks each vendor for one in writing. Cognigy publishes a "HIPAA Type 2 Final Report 2026" and no BAA terms. Card handling differs. Cognigy reports "PCI DSS - SAQ D, Merchant", the PCI Council's self-assessment form for merchants, while Sierra says it "holds PCI DSS Level 1 Service Provider certification". Sierra also reports ISO 42001. On data handling, Sierra says personal information shared with an agent is automatically encrypted and masked. Bland offers a 99.9% uptime SLA on every plan. A team reviewing either vendor also reviews every AI company behind it. Bland is full stack, so a security team reviews one AI company, and Bland's language model is closed source and developed by Bland itself. ## Which sounds more human, Cognigy or Sierra? Neither Cognigy nor Sierra has a voice of its own placing on Design Arena's Audio Realism Bench as of 4 August 2026, and Bland Speech v3 ranked 1st of 13 AI voices at 1365, second only to real human recordings. Cognigy supports ElevenLabs among the voice vendors a customer can connect. Eleven v3 placed 12th of 13 at 938, below Bland Speech v3 at 1365, and it is an outside voice on Cognigy, not one Cognigy built. The test is blind, with vetted native speakers choosing which of two voices reads one script more like a real person. See [Design Arena's published results](https://notes.designarena.ai/audio-realism-benchmark-measuring-realism-in-audio-models/). ## How much do Cognigy and Sierra cost? Neither Cognigy nor Sierra publishes a rate, so a buyer gets a quote from sales for either one, while Bland publishes $0.14 a minute on self-serve Start and $0.12 a minute plus $299 a month on self-serve Build for all of its AI, before phone, as of November 2026. ### Cognigy pricing Cognigy sells by quote, and meters billable conversations, concurrent lines, and knowledge queries. A billable conversation is limited to up to 50 user inputs within a 24-hour period, voice lines are sold as concurrent lines on Voice Gateway, and Knowledge AI is licensed by knowledge chunks and queries. On top sit a customer's own language model vendor, speech vendor, and carrier. Ownership adds a second billing model. For customers of NICE CXone, Cognigy says usage is billed per conversation with "up to 10 minutes per call" counting as 1 conversation, so a buyer asks which model a quote uses. - **Billable conversation:** Per conversation of up to 50 user inputs in 24 hours, with no rate published - **Voice Gateway:** Packages of concurrent lines under a separate license, with no price published - **Knowledge AI:** Charged per knowledge query and knowledge chunk, with no rate published - **PCI Vault:** Additional license plus Agent Copilot, for conversations with human agents, with no price published ### Sierra pricing Sierra says "Sierra gets paid only when we complete a task for you", and ties each charge to criteria agreed upfront. A conversation that goes unresolved usually costs nothing, and Sierra offers a blended approach where routing or greeter-style interactions are billed per conversation regardless of the outcome. Because Sierra publishes no rate, the definition of an outcome is a point to settle in a contract before signing. - **Outcome-based pricing:** Paid per resolved conversation or other agreed outcome, with no published rate - **Routing and greeter interactions:** Can be priced per conversation instead ### Bland pricing Bland publishes one number per plan, and that number covers its language model, transcription, and speech with no token charges. A minute is $0.14 on self-serve Start, or $0.12 on self-serve Build with a $299 monthly platform fee. Phone is billed separately, on a customer's own carrier or on Bland's at pass-through cost. Enterprise pricing is custom, set with Bland's sales team. A per-minute rate lets a finance team forecast from a price before talking to sales, which neither metered conversations nor outcome billing allows, and Cognigy and Sierra can't be set beside Bland's self-serve $0.14 or $0.12 on one basis until they quote. ### What does each Bland plan include? Enterprise is the plan regulated teams buy. It adds native iMessage agents alongside SMS and web chat, warm transfers, guardrails, a BAA, SSO, data residency, dedicated orchestration with dedicated GPUs run by Bland, and forward-deployed engineers who work beside a customer's team, with concurrency contracted to its volume and custom pricing. | Included | Self-serve: Start | Self-serve: Build | Enterprise (custom) | |---|---|---|---| | Price per minute | $0.14 | $0.12 | Custom | | Platform fee | $0 | $299 a month | Contracted to volume | | Transfer time per minute | $0.05 | $0.04 | Custom | | Concurrent calls | 10 | 50 | Custom | | Calls a day | 100 | 2,000 | Unlimited | | Knowledge bases | 10 | 50 | Unlimited | | Voices | 1 | 5 | Unlimited | | Uptime SLA | 99.9% | 99.9% | 99.9% | | Pathways, integrations, and automations | Yes | Yes | Yes | | iMessage, SMS, and web chat | No | No | Yes | | Warm transfers and guardrails | No | No | Yes | | BAA, SSO, and data residency | No | No | Yes | | Dedicated orchestration and GPUs | No | No | Yes | | Forward-deployed engineers | No | No | Yes | ## Why do enterprises pick Bland over both? Enterprises pick Bland over both Cognigy and Sierra because one company builds every AI model on a call, the self-serve rate is published, and Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland. Bland has more than 250 enterprise customers and has handled over 1.3 billion calls, and it publishes sub-200ms latency. Bland also runs branded iMessage agents natively on Enterprise, which send and receive photos, videos, files, voice memos, and tapbacks, and share the same pathways as its voice agents. On Enterprise, forward-deployed engineers work beside a customer's team on its first agent. ![Bland's trust page, which reads Pass security review on day one, with voice, text to speech, transcription, and language models all owned and operated by Bland.](/images/compare/bland-trust.jpg)

Use Bland when

Use Cognigy when

Use Bland when

Use Sierra when

Where a team's needs point away from either vendor, the reasons come from what each says. For Cognigy: - Teams that need its card-data vault on calls an AI agent handles, because its PCI Vault is documented for "conversations with human agents" - Want voice included, because Voice Gateway is an add-on that "can't be used independently" and needs a separate license - Teams that need redaction they can trust on its own, because Cognigy says "Data redaction uses regex patterns" that can miss data or match the wrong digits - Need the most realistic voices, because Bland Speech v3 ranked first among AI voices on Audio Realism Bench on 4 August 2026 at 1365, and the one model Cognigy's vendor list names there scored 938 For Sierra: - Want every charge tied to a finished outcome, because Sierra says routing and greeter interactions can be priced on conversation count "regardless of the outcome" - Teams that need to know whose voice and transcription are on their calls, because Sierra doesn't publish a vendor for either - Teams that want proof of how human an agent sounds, because Bland Speech v3 ranked first among AI voices on Audio Realism Bench on 4 August 2026 at 1365, and no voice carrying Sierra's name was ranked - Teams that want to build and test an agent before signing, because Sierra has no self-serve mode

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### What results look like with Bland Idaho Housing and Finance Association saves $750,000 a year by replacing its IVR with Bland, which handles 4,000 inbound calls a day and cut average call time by 20%. > "We save thousands of dollars a day." Greg Blake, Chief Information Officer, Idaho Housing and Finance Association ### How was this comparison made? Cognigy and Sierra were compared on what each runs on, how each bills, setup, security, deployment, and voice realism, using each company's published pages read on 5 November 2026. Voice scores come from Design Arena's chart of 4 August 2026. Bland vs Cognigy and Bland vs Sierra go further, as does the [comparison hub](/compare), and a [demo](https://www.bland.ai/book-a-demo) built on a real workflow is the quickest next step. For the same question about other vendors, read [Sierra vs Decagon](/blog/sierra-vs-decagon) or [Retell vs Vapi](/blog/retell-vs-vapi), and see how switching works in [Sierra alternative for enterprises](/alternatives/sierra) and [Best Cognigy alternatives](/blog/cognigy-alternatives). A [Cognigy review](/blog/cognigy-review) and a [Decagon review](/blog/decagon-review) cover single vendors in depth. Anyone weighing Cognigy against another vendor can open [Cognigy vs Kore.ai](/blog/cognigy-vs-kore-ai), and a [Kore.ai review](/blog/kore-ai-review) covers that vendor on its own. ## Frequently asked questions ### Is Cognigy better than Sierra? Bland is the better pick than either Cognigy or Sierra for phone calls, because one company builds every AI model on a call and the rate is published. Cognigy suits a team that wants to configure its own platform and Sierra suits a team that wants a managed agent, so the choice between those two turns on who should do the assembling. ### How much do Cognigy and Sierra cost? Neither Cognigy nor Sierra publishes a rate. Cognigy meters billable conversations, concurrent voice lines, and knowledge queries under separate licenses, and Sierra bills by outcome, with some interactions billed per conversation. Bland publishes $0.14 a minute on self-serve Start and $0.12 a minute on self-serve Build, before phone. ### Do Cognigy and Sierra support iMessage? Cognigy doesn't offer iMessage agents, and supports Apple Business Chat only as a RingCentral Engage setting as of November 2026, and Sierra supports Apple Business Chat. Bland runs branded iMessage agents natively on Enterprise, which share the same pathways as its voice agents. ### Do Cognigy and Sierra build their own AI models? Neither Cognigy nor Sierra builds the whole stack. Cognigy connects a customer's choice of outside language model and speech vendor, while Sierra builds on a constellation of frontier, open-weight, and proprietary models. Bland builds and runs its own language, speech, and transcription models. ### Does Bland use an open-source model? No, Bland operates a closed-source model that it developed itself, so its language model isn't an open-source model and no outside AI lab sits behind it. ### Is Bland only for outbound calls? No, Bland runs inbound and outbound calls, including AI receptionist and contact center work, and it also runs SMS and web chat. ### Is Bland only for developers? No, Bland isn't only for developers. Pathways gives teams a visual builder, Norm helps build agents, and on Enterprise forward-deployed engineers build alongside a customer's team. ### How much does Bland cost per minute? Bland costs $0.14 per minute on its self-serve Start plan and $0.12 per minute on self-serve Build, which adds a $299 monthly platform fee, and phone is billed separately. Bland replaced its earlier flat $0.09 rate with these plans in December 2025. Enterprise pricing is custom, set with Bland's sales team. ### Does Bland's rate include phone? No, Bland's rate covers its language model, transcription, and speech, and phone is billed separately, on a customer's own carrier or on Bland's at pass-through cost.