# Synthflow vs Vapi (2026): Which should enterprises buy? By Samuel Oram-Jones Synthflow sells one annual enterprise contract with no public rate, and Vapi sells hosting by the minute with every other part billed at provider cost. This comparison covers what each runs on, how each bills, what each says about security and deployment, and where Bland fits for phone calls, as of November 2026. ## Which is better, Synthflow or Vapi? Bland is the better pick than either Synthflow or Vapi for enterprise phone calls as of November 2026, because Bland builds and runs every AI model on a call, publishes a self-serve per-minute rate, and Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland. Between the two, the choice is a visual designer in a sales-led contract or an API with each provider chosen by hand. Synthflow suits teams that want a node-based Flow Designer and a vendor that scopes launch support into the agreement, while Vapi suits developers who want to pick a transcriber, a language model, and a voice themselves. | Feature | Bland | Synthflow | Vapi | |---|---|---|---| | AI on each call | Full stack | Mixed | Outsourced | | Audio Realism Bench score, 4 August 2026 | #1 AI voice, 1365 | ElevenLabs, on Synthflow: #12, 938 | OpenAI, on Vapi: #4, 1119 | | iMessage | Native | No | No | | AI rate per minute | $0.12-$0.14 self-serve | Quote | $0.05 hosting only |
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. - **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. - **iMessage:** iMessage lets an agent text customers on a channel they already use. Bland offers it natively on Enterprise. - **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. Synthflow publishes no per-minute rate and sells an annual contract. Vapi's $0.05 is hosting only, with language model, transcription, and voice billed at provider cost on top.
## How do Synthflow and Vapi differ? The biggest difference between Synthflow and Vapi is who stands behind a call. Synthflow bundles its own orchestration, text-to-speech, and speech-to-text with models from other companies, and Vapi hosts a call and hands the language model and transcription to companies a developer chooses. Bland, a full stack provider, builds all three itself. ### Synthflow overview Synthflow sells an annual enterprise agreement scoped to call volume, phone system, integrations, security needs, and launch support. It says it has no free plan or trial and no rate by the minute. Agents are built in the dashboard or through the API, with a choice of Flow Designer or Prompt Builder, and templates or JSON import. Flow Designer lays a call out as nodes, and Synthflow also offers its own Synthflow LLM, Synthflow TTS, and Synthflow STT. Its default voice is still an ElevenLabs model, and Synthflow says "GPT and other third-party models are only available on Enterprise plans." Its AI transparency statement says agents are "Powered by proprietary orchestration and models from OpenAI, ElevenLabs, Deepgram, and custom in-house logic." Synthflow doesn't offer iMessage agents.

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### Vapi overview Vapi is a developer platform that hosts voice agents. A team configures voice, conversation flow, telephony, and integrations through its API, and swaps the transcriber, the language model, and the voice from a menu of providers such as Deepgram, OpenAI, and ElevenLabs, or uses Vapi Voices, its own curated set. Each provider is billed at cost on top of a hosting fee of five cents a minute. That flexibility comes with ownership of the combination. Vapi says "Without any fallback plan configured, your call will end with an error if your chosen transcription provider fails." Vapi doesn't offer iMessage agents.

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### How do Synthflow and Vapi set up and connect? A first live call looks different on each. Synthflow starts with a sales conversation, because it sells only an annual agreement, and where an agreement includes launch support its forward-deployed engineers implement, test, and launch agents with the customer's team. Its templates and Flow Designer suit teams that want a builder rather than a codebase. Vapi has a developer wire an agent through its API, and its chat and SMS support carries a limit: "Only customers can initiate conversations - assistants cannot send the first message." Synthflow runs WhatsApp and SMS chat agents in US workspaces only. Bland connects to an existing carrier over [SIP](https://docs.bland.ai/agents/sip), the standard link between a phone system and a voice platform, so existing numbers can stay where they are. Bland runs its own SIP signaling and media servers, so every call is set up, hosted, and processed on Bland infrastructure with no third-party telephony provider in the path. ### How do Synthflow and Vapi handle security and uptime? Synthflow says its infrastructure is certified across SOC 2, HIPAA, PCI DSS, and GDPR, and Vapi says it is SOC 2 Type II attested with GDPR handling for EU data. On HIPAA, Synthflow executes a BAA, a contract that lets a vendor handle patient information, at contract signing for customers using its HIPAA Setting, and says "By default, the HIPAA Setting is disabled". Vapi sells HIPAA mode as a $2,000 a month add-on, and says HIPAA mode and zero data retention are "mutually exclusive". Deployment differs too. Synthflow hosts a workspace on a US or EU cluster and says "Cluster selection is permanent", so a different region means creating a new workspace and migrating agents. Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland. Both set speed promises against paper. Synthflow advertises latency under 500 milliseconds and four nines of uptime on its enterprise page, while its terms test for "P90 ≤ 2,800 ms bot response time", meaning nine in ten responses within 2.8 seconds. Vapi advertises average latency-to-response under 500 milliseconds, and its FAQ puts end-to-end voice processing at "typically around 800 milliseconds". Vapi's engineering blog is titled "How We Achieved 99.99% Reliability At Vapi", while Vapi offers a 99% uptime SLA on Pro and a higher figure only on Premier, which is sold through sales. Pro's 99% allows about 7.2 hours of downtime over 30 days. Bland publishes sub-200ms latency and offers a 99.9% uptime SLA on every plan. A team reviewing either vendor also reviews every AI company behind it. OpenAI, ElevenLabs, and Deepgram are among the companies whose models power Synthflow's agents. Vapi's terms, last updated 14 September 2026, sort third-party services into Vapi Subprocessors, Optional Providers, and Customer-Managed Providers, and say "Vapi does not control, and is not responsible for, any Optional Provider or Customer-Managed Provider". A subprocessor is an outside company handling a vendor's data on its behalf, so a buyer asks which category each AI company falls in. Bland's language model is closed source and developed by Bland itself. ## Which sounds more human, Synthflow or Vapi? Neither Synthflow nor Vapi has a voice of its own with a score on Design Arena's Audio Realism Bench of 4 August 2026, and Bland Speech v3 ranked 1st of 13 AI voices at 1365, second only to real human recordings. Synthflow's default voice is ElevenLabs Flash, which has no score on that bench, and neither does Synthflow TTS. Eleven v3, which a customer can switch to, ranked 12th at 938. Vapi Voices have no score on that bench either. The outside voices a customer can pick on Vapi all scored below Bland Speech v3, with GPT Realtime 2 highest at 1119, 4th. 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 Synthflow and Vapi cost? Synthflow publishes no rate, so a buyer gets a quote for an annual agreement, while Vapi publishes a hosting fee of five cents a minute that excludes the models, and Bland publishes $0.14 a minute on its self-serve Start plan and $0.12 a minute plus $299 a month on self-serve Build for all of its AI, before phone, as of November 2026. ### Synthflow pricing Synthflow sells one annual agreement, so the first price a buyer sees is a quote. Its terms say any unused volume "shall expire at the end of the applicable Billing Period" without a refund, and that fees are due for the whole period whether or not the software is used. Purchased phone numbers cost $1.50 a month. Synthflow's terms include: - **Contract:** Annual agreement only, with no free plan or trial - **Rates:** No public per-minute rate - **Contract terms:** Usage volume can't be decreased ### Vapi pricing Vapi charges five cents a minute for hosting and bills the transcriber, language model, and voice at provider cost, which Vapi's pricing calculator prices at up to $0.0099 for transcription, $0.0452 for a language model, and $0.0238 for voice, with Twilio outbound phone at $0.014. Vapi promises "Provider costs with no markup", so a price change at any provider reaches a bill. Vapi's terms say "Unless you have limited the traffic flow to certain limits, we do not stop incoming voice calls" and "you are responsible for payment of all the minutes utilized on our Platform", so limits matter before a campaign runs. Vapi also bills: - **HIPAA add-on:** $2,000 a month - **Pro package:** 10% of hosting, $999 monthly minimum - **Extra concurrency:** $10 a month per line - **Language, voice, and transcription:** Billed at provider cost on top of $0.05 hosting ### 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 the self-serve Start plan, 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. Bland's rate can be set beside Vapi's calculator on one basis, since both are before phone, and Synthflow can't be set beside either until it quotes. For how the two billing models differ in general, read [Usage vs outcome-based pricing](/blog/usage-vs-outcome-based-pricing). ### 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 Synthflow and Vapi because one company builds every AI model on a call, its 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. A security team reviews one AI company instead of a chain of them, and finance can price a minute before a sales call. 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 also moves an agent from staging to production only when chosen simulated test cases pass chosen judges, and its evaluations grade call audio as well as the transcript, so tone and satisfaction count. ![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 Synthflow when

Use Bland when

Use Vapi when

Where a team's needs point away from either vendor, the reasons come from what each says. For Synthflow: - Teams that want to try it before signing, because it sells an annual contract with no free plan or trial - Might ever need to scale down, because its terms say "Usage Volume ordered cannot be decreased" - Need personal details removed from recordings, because Synthflow says "Real-time audio is not affected" by redaction - 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 voice Synthflow offers in those results ranked 12th at 938 For Vapi: - Teams that want one company answering for every AI part of a call, because its terms say "Vapi does not control, and is not responsible for, any Optional Provider or Customer-Managed Provider" - Want HIPAA handling without a $2,000 a month add-on, because Vapi prices HIPAA mode as a separate line - Can't have calls fail when a provider does, because Vapi says "Without any fallback plan configured, your call will end with an error if your chosen transcription provider fails" - 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 Vapi's highest voice there ranked 4th at 1119

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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? Synthflow and Vapi were compared on what each runs on, how each bills, setup, security, deployment, and voice realism, using each company's published pages and terms read on 5 November 2026. Voice scores come from Design Arena's chart of 4 August 2026. Bland vs Synthflow and Bland vs Vapi 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 [Retell vs Vapi](/blog/retell-vs-vapi), [Synthflow vs Voiceflow](/blog/synthflow-vs-voiceflow), or [Sierra vs Decagon](/blog/sierra-vs-decagon), and see how switching works in [Synthflow alternative for enterprises](/alternatives/synthflow) and [Vapi alternative for enterprises](/alternatives/vapi). A [Synthflow review](/blog/synthflow-review) covers one of the two in depth. ## Frequently asked questions ### Is Synthflow better than Vapi? Bland is the better pick than either Synthflow or Vapi for phone calls, because one company builds every AI model on a call and the rate is published. Synthflow sells a sales-led annual agreement with a visual designer and Vapi sells an API with hosted infrastructure, so the choice between those two turns on whether a team wants a builder or a toolkit. ### Is Synthflow cheaper than Vapi? Public prices can't settle it, because Synthflow publishes no rate. Vapi's hosting is five cents a minute with a transcriber, language model, and voice billed at provider cost on top, and Synthflow quotes an annual agreement. Bland publishes $0.14 a minute on its self-serve Start plan and $0.12 a minute on self-serve Build, before phone. ### Do Synthflow and Vapi support iMessage? Synthflow doesn't offer iMessage agents and Vapi doesn't offer iMessage agents, as of November 2026. Bland runs branded iMessage agents natively on Enterprise, which share the same pathways as its voice agents. ### Do Synthflow and Vapi build their own AI models? Synthflow and Vapi each build only part of their AI. Synthflow has its own language model, text-to-speech, and speech-to-text, but its default voice is ElevenLabs and it credits models from OpenAI, ElevenLabs, and Deepgram, while Vapi has its own Vapi Voices and runs the language model and transcription on companies a developer picks. Bland builds and runs its own language, speech, and transcription models. ### Are Synthflow and Vapi HIPAA compliant? Both support HIPAA with conditions. Synthflow's HIPAA Setting is off by default and its BAA is executed at contract signing, and Vapi signs a BAA and turns on HIPAA mode as a $2,000 a month add-on. Bland includes a BAA on Enterprise, with no outside AI company to review. ### 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.