# Best AI telemarketing software in 2026: Bland, Retell, Synthflow, Vapi

By Samuel Oram-Jones

AI telemarketing software places sales and prospecting calls with a voice AI agent instead of a human dialer, and Bland, Retell, Synthflow, and Vapi are four providers a team can run it on. This comparison covers who builds the AI, what a minute costs, consent, security, and uptime, as of November 2026.

## Which is best, Bland, Retell, Synthflow, or Vapi?

For enterprise AI telemarketing, Bland is the best of the four as of November 2026, because it is full stack and runs inbound and outbound calls on its own language, speech, and transcription models, and it publishes one self-serve rate that covers all of its AI. Retell and Vapi run calls on outside models, and Synthflow mixes its own parts with models from OpenAI, ElevenLabs, and Deepgram.

| Feature | Bland | Retell | Synthflow | Vapi |
|---|---|---|---|---|
| AI on each call | Full stack | Outsourced | Mixed | Outsourced |
| Audio Realism Bench score, 4 August 2026 | #1 AI voice, 1365 | OpenAI, on Retell: #4, 1119 | ElevenLabs, on Synthflow: #12, 938 | OpenAI, on Vapi: #4, 1119 |
| iMessage | Native | No | No | No |
| HIPAA with a BAA | Included on Enterprise | Supported | Supported | $2,000/month |
| PCI DSS | Self-attested | No | Supported | Supported |
| AI rate per minute | $0.12-$0.14 self-serve | $0.07-$0.31 | Quote | $0.05 hosting only |

<details><summary>What these rows mean</summary>

- **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.
- **HIPAA with a BAA:** A Business Associate Agreement, or BAA, is the contract that lets a vendor handle patient information under HIPAA. Bland includes its BAA on Enterprise. Vapi sells HIPAA mode as a $2,000 monthly add-on.
- **PCI DSS:** PCI DSS is a security standard from the card industry for handling card details. Bland self-attests to v4.0.1 and shares its attestation under NDA on Enterprise. Retell gives no PCI status, and it bars card data unless it agrees in writing.
- **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. Retell advertises $0.07 to $0.31 a minute, and one language model alone lists at $0.384 a minute. 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.

</details>

## How do Bland, Retell, Synthflow, and Vapi compare?

A sales campaign leans on the same three AI parts as any other call: transcription that turns a prospect's speech into text, a language model that decides what the agent says, and speech that says it back. Bland keeps all three, while Retell and Vapi rent two, and Synthflow splits them between its own parts and outside ones.

That matters on a cold call, where a prospect decides within seconds whether to hang up, because every outside company in the chain is one more place for delay or a changed voice to creep in. Teams booking meetings from those calls can compare [AI appointment setters](/blog/bland-vs-synthflow-vs-retell-vs-11x) next.

On latency, Bland publishes sub-200ms. Vapi puts average latency-to-response under 500ms on its enterprise page, while its FAQ says "typically around 800 milliseconds for end-to-end voice processing". Synthflow advertises latency under 500ms, while its contract sets "P90 ≤ 2,800 ms bot response time", and Retell says "~600ms latency".

A telemarketing campaign is mostly a list dialed at volume, with live people picking up the interested prospects. On Bland, batch calls let a team call a whole list or start calls from Bland, Salesforce, and HubSpot events, and warm transfer on Enterprise has the agent brief a team member on a second line before bringing the prospect in.

### Bland overview

Bland is a full stack voice AI provider for enterprises and contact centers running high-stakes inbound and outbound calls at volume. Its language model is closed source and developed in-house, so no outside AI lab sits in a call, and it publishes sub-200ms latency.

Teams build calls in [Pathways](https://www.bland.ai/product), which lays a conversation out as connected steps that can be tested before launch, and a [testbed](https://docs.bland.ai/agents/testbed) re-runs one turn of a real conversation against an edited prompt. Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland. On [Enterprise](https://www.bland.ai/pricing), branded iMessage agents run natively on the same pathways as voice.

A new Bland agent version takes a small share of calls first, Bland benchmarks it against the previous version, and the rollout pauses when a KPI such as escalation rate gets worse.

<div class="cmp-proscons cmp-proscons-own"><div class="cmp-proscons-pros"><p><strong>Pros</strong></p><ul><li>One AI company on every call, so a security team reviews one vendor</li><li>One published rate for all of its AI, with no token charges</li><li>#1 of 13 AI voices on Audio Realism Bench, 4 August 2026</li><li>Dedicated orchestration and dedicated GPUs run by Bland, on Enterprise</li><li>Native iMessage agents on Enterprise, sharing pathways with voice</li><li>Staged releases that pause a new agent version when it performs worse than the last</li><li>Its own SIP and media servers, with no outside telephony provider in the call path</li></ul></div><div class="cmp-proscons-cons"><p><strong>Cons</strong></p><ul><li>Overkill for a small prototype, because Bland is built for production calls at volume</li></ul></div></div>

### Retell overview

Retell sells voice infrastructure at $0.055 per minute, and a customer assembles the rest. A team picks a language model such as GPT, Claude, or Gemini, a voice from Retell or from a company such as ElevenLabs, Cartesia, MiniMax, or OpenAI, and Deepgram, Azure, Soniox, or AssemblyAI handle transcription.

For outbound, Retell charges $0.10 per outbound call for Branded Call, and calls above a customer's concurrency limit cost $0.10 per minute for the whole call, two lines that grow with campaign size.

<div class="cmp-proscons" data-rival="retell"><div class="cmp-proscons-pros"><p><strong>Pros</strong></p><ul><li>A team can choose its language model and voice vendor</li><li>No platform fee and a self-serve start</li></ul></div><div class="cmp-proscons-cons"><p><strong>Cons</strong></p><ul><li>Language and transcription models come from other companies</li><li>Branded Call and calls above a concurrency limit add to a campaign's bill</li><li>99.5% uptime in its contract against more than 99.9% in its advertising</li><li>No PCI status, and card data barred unless it agrees in writing</li><li>No iMessage agents</li></ul></div></div>

### Synthflow overview

Synthflow sells AI voice agents through one annual enterprise agreement, with telephony, integrations, and launch support scoped in, and it has no free plan or trial. Synthflow says it is "Powered by proprietary orchestration and models from OpenAI, ElevenLabs, Deepgram, and custom in-house logic", and its default voice is an ElevenLabs model next to its own Synthflow TTS.

Synthflow's WhatsApp and SMS chat channels are available in US workspaces only, and Synthflow supports 30+ languages.

<div class="cmp-proscons" data-rival="synthflow"><div class="cmp-proscons-pros"><p><strong>Pros</strong></p><ul><li>SOC 2 Type 2, ISO/IEC 27001, HIPAA, and GDPR coverage listed</li><li>Forward-deployed engineers can launch agents with a team where the agreement includes them</li></ul></div><div class="cmp-proscons-cons"><p><strong>Cons</strong></p><ul><li>An annual contract with no free plan or trial, so a team commits before it can test a campaign</li><li>Models from OpenAI, ElevenLabs, and Deepgram sit behind its agents</li><li>No iMessage agents</li></ul></div></div>

### Vapi overview

Vapi hosts calls at $0.05 per minute and exposes each part of a setup through its API. A customer's transcriber, language model, and voice are billed at provider cost on top, and Vapi lists its own curated Vapi Voices next to voices from companies such as ElevenLabs, Cartesia, and OpenAI.

That freedom comes with upkeep, because every part is also the customer's to keep running. Vapi says "Without any fallback plan configured, your call will end with an error if your chosen transcription provider fails", and extra concurrent call lines cost $10 each per month.

<div class="cmp-proscons" data-rival="vapi"><div class="cmp-proscons-pros"><p><strong>Pros</strong></p><ul><li>Developers can wire each provider through an API</li><li>Models pass through at provider cost with no markup</li></ul></div><div class="cmp-proscons-cons"><p><strong>Cons</strong></p><ul><li>Language model and transcription come from companies a customer picks</li><li>Each added provider is another vendor to test, pay, and review</li><li>No iMessage agents</li></ul></div></div>

## Which sounds more human, Bland, Retell, Synthflow, or Vapi?

Bland Speech v3 ranked first of 13 AI voices on Design Arena's Audio Realism Bench of 4 August 2026, at 1365, above every outside voice available on Retell, Synthflow, and Vapi. None of the platforms' own voices were in those results.

Design Arena's Audio Realism Bench is a blind listening test in which vetted native speakers pick whichever of two voices sounds more like a real person. The highest voice on Retell and Vapi was GPT Realtime 2, an OpenAI voice, 4th at 1119. The one Synthflow voice in those results, Eleven v3, ranked 12th at 938, and Synthflow's default ElevenLabs Flash was not in them.

Scores come from [Design Arena's published results](https://notes.designarena.ai/audio-realism-benchmark-measuring-realism-in-audio-models/) of 4 August 2026.

## How much do they cost?

Bland's self-serve Start plan costs $0.14 per minute and self-serve Build costs $0.12 per minute with a $299 monthly platform fee, covering all of its AI, while Retell and Vapi each advertise a number that covers a different slice of a call and Synthflow publishes no rate, as of November 2026. Phone sits on top of every one of them. Enterprise pricing is custom, set with Bland's sales team.

### Bland pricing

Bland publishes one number per plan, and it covers the language model, transcription, and speech with no token charges. Phone is billed separately, on a customer's own carrier or on Bland's at pass-through cost, as are transfer minutes at $0.05 a minute on self-serve Start and $0.04 on self-serve Build, and a $0.015 minimum on each outbound attempt using Bland's telephony.

Warm transfer, a BAA, and dedicated GPUs run by Bland sit on Enterprise. Teams weighing sales tools beyond calling can read [Regie.ai vs 11x vs Artisan](/blog/bland-vs-regie-ai-vs-11x-vs-artisan).

### Retell pricing

Retell advertises $0.07 to $0.31 per minute, and where a team lands depends on what it picks. The language model, voice infrastructure, voice, and phone each bill on their own line, one language model alone lists at $0.384 per minute, and Retell's Twilio phone line adds $0.015.

Once a prompt passes 4,000 tokens Retell scales billed time, so a 12,000-token agent bills a 60-second call as 180 seconds.

### Synthflow pricing

Synthflow says it has "no free plan or trial and no rate by the minute", so a team gets a quote scoped to its call volume, phone system, and integrations. Its terms add that "Usage Volume ordered cannot be decreased", which makes a first campaign's forecast a commitment. Purchased numbers cost $1.50 a month.

### Vapi pricing

Vapi's $0.05 is hosting only. Transcription tops out at $0.0099, a language model at $0.0452, and a voice at $0.0238 per minute on its calculator, each billed at provider cost, and Twilio outbound minutes on Vapi add up to $0.014.

Vapi's Pro package takes 10% of hosting with a $999 monthly minimum. Vapi says "Models pass-through at cost", so a price change at any provider reaches a bill.

### Value comparison

The bills below price the AI in one minute before phone, using Bland's published self-serve Start rate, Retell on GPT-4.1 with an ElevenLabs Flash voice, and the top of every range on Vapi's calculator. Each total rests on its own basis, so none of them ranks against another, and Synthflow has no per-minute figure to put beside them.

Retell's bill runs across three companies and Vapi's across four, while Bland's is one rate from one company.

| Vendor | What a minute pays for | Total per minute | Phone |
|---|---|---|---|
| Bland Start (self-serve) | All AI: model, transcription, speech $0.14 | $0.14 before phone | Billed separately at carrier cost |
| Retell | Voice infrastructure $0.055, GPT-4.1 $0.045, ElevenLabs Flash voice $0.04 | $0.14 before phone | Twilio at $0.015 a minute, billed on top |
| Vapi | Hosting $0.05, Transcription $0.0099, Language model $0.0452, Voice $0.0238 | $0.1289 before phone | Free on Vapi numbers, billed on top on Twilio at up to $0.014 a minute |

Bland Start (self-serve): Self-serve Start has no platform fee. Self-serve Build is $0.12 a minute plus $299 a month. Phone and transfers bill separately. Retell: Retell Voice Infra, GPT-4.1, and an ElevenLabs Flash voice, before Twilio phone minutes. Vapi: Hosting plus the top of each range on Vapi's pricing calculator, before phone.

### 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 |

## How do they handle security and uptime?

Bland, Retell, Synthflow, and Vapi all report SOC 2 and GDPR, and they part ways on medical calls, card payments, deployment, and uptime. Bland offers a 99.9% uptime SLA on every plan.

Retell markets "HIPAA-Compliant Patient Calls" and gives no PCI status. It advertises "We guarantee >99.9% uptime", while its contract promises "commercially reasonable efforts" at 99.5%, excluding up to six hours a month of scheduled maintenance.

Synthflow advertises "99.99% Uptime" and says its infrastructure is certified across SOC 2, HIPAA, PCI DSS, and GDPR, with support and availability terms set in each agreement. It runs each enterprise workspace in a single-region US or EU cluster, and the choice is permanent.

Vapi sells HIPAA mode as a $2,000 monthly add-on and offers a PCI mode. Vapi lists a "99% uptime SLA" on its Pro package and a "99.9% uptime SLA" on Premier.

Bland includes a BAA, the contract HIPAA requires before a vendor handles patient information, on Enterprise. Its [security program](https://www.bland.ai/trust-security) self-attests to [PCI DSS](https://www.pcisecuritystandards.org/standards/pci-dss/) v4.0.1 and holds FedRAMP 20x Class A. Bland's pages on [HIPAA compliant voice AI](/hipaa-compliant-voice-ai) and [PCI compliant voice AI](/pci-compliant-voice-ai) go further.

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.

![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)

### Who is responsible for consent and Do Not Call rules on a sales call?

On all four platforms, consent and Do Not Call duties stay with the business placing the call. The FCC ruled in February 2024 that AI-generated voices count as artificial voices under the TCPA, so a sales call from any of these agents generally needs the prospect's prior express consent, and a business should have a lawyer review its call lists, scripts, and calling hours before a campaign dials.

On Bland, four TCPA guardrails come built in: AI disclosure, recording disclosure, self-introduction, and opt-out. Guardrails run through the whole call, and on a violation an agent can end the call, transfer it, or take a custom action.

## Which should a team pick?

A team running outbound sales that needs dedicated GPUs run by Bland, one AI company to review, and the top-ranked voice on Design Arena's August 2026 chart should pick Bland, with more than 250 enterprise customers and over 1.3 billion calls handled. Bland's published rates cover all of its AI, forward-deployed engineers work beside a customer's team on Enterprise, and its language model is a closed-source model it developed itself.

Teams that care most about keeping calls in-house can also read about [Voice AI agents for call containment](/blog/best-voice-ai-call-containment).

<div class="cmp-usewhen"><div class="cmp-usewhen-own"><p><strong>Use Bland when</strong></p><ul><li>A team wants dedicated orchestration and dedicated GPUs run by Bland</li><li>A security team wants to review one AI company, not a chain of them</li><li>Prospects should hear the most realistic voice</li><li>A team wants Bland's forward-deployed engineers to build and launch its first agent alongside it, on Enterprise</li></ul></div><div><p><strong>Use Retell when</strong></p><ul><li>A small engineering team wants to monitor, test, and toggle between different language models and voice vendors</li><li>Campaign volume is modest, and a team will manage its own vendor bills</li><li>A security team will review each AI vendor the team adds</li></ul></div></div>

<div class="cmp-usewhen"><div class="cmp-usewhen-own"><p><strong>Use Synthflow when</strong></p><ul><li>A team signs a sales-scoped annual agreement with launch support built in</li><li>A team runs WhatsApp and SMS chat in US workspaces alongside calls</li></ul></div><div><p><strong>Use Vapi when</strong></p><ul><li>Developers wire each transcriber, model, and voice through an API</li><li>A team owns the whole assembly, including what happens when one provider fails</li></ul></div></div>

### 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?

Bland, Retell, Synthflow, and Vapi were compared on who builds the AI, price per minute with each basis stated, voice realism, deployment, security, and uptime, using each company's own pricing, terms, and documentation as of November 2026. Voice scores come from Design Arena's chart of 4 August 2026.

### Related comparisons

- Bland against one rival: [Bland vs Retell](/compare/bland-vs-retell), [Bland vs Synthflow](/compare/bland-vs-synthflow), and [Bland vs Vapi](/compare/bland-vs-vapi)
- Reviews: [Retell AI review](/blog/bland-ai-vs-retell-ai) and [Synthflow review](/blog/synthflow-review)
- Rivals head to head: [Retell vs Vapi](/blog/retell-vs-vapi) and [Synthflow vs Vapi](/blog/synthflow-vs-vapi)
- Outbound: [AI outbound dialers](/blog/best-ai-outbound-dialers)
- All pages: Bland's [comparison hub](/compare)

## Frequently asked questions

### Which is better for AI telemarketing, Bland, Retell, Synthflow, or Vapi?

Bland is the better choice for enterprise AI telemarketing because it is full stack and publishes one self-serve rate for all of its AI. Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland. Retell and Vapi rely on outside models, and Synthflow uses models from OpenAI, ElevenLabs, and Deepgram next to its own.

### Is AI telemarketing legal?

It can be, and the business placing the calls carries the duty. The FCC ruled in February 2024 that AI-generated voices count as artificial voices under the TCPA, so a sales call generally needs the prospect's prior express consent, and Do Not Call requests must be honored on every platform.

### 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.

### Which of the four is cheapest per minute?

None of the four can be ranked on the advertised figure, because each covers a different slice of a call. Vapi's $0.05 is hosting only, Retell advertises $0.07 to $0.31, Synthflow publishes no rate, and Bland's $0.14 on self-serve Start or $0.12 on self-serve Build covers all of its AI before phone, which is billed on top of every one.

### 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. Retell bills phone on its own line at $0.015 per minute on Twilio, Synthflow charges $1.50 a month for a purchased number, and Vapi's own numbers are free.

### Does Retell, Synthflow, or Vapi support iMessage?

Retell doesn't offer iMessage agents, 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 send and receive photos, videos, files, voice memos, and tapbacks, and share the same pathways as its voice agents.

### Which has the most realistic voice?

Bland, on Design Arena's chart of 4 August 2026, where Bland Speech v3 ranked 1st of 13 AI voices at 1365, and GPT Realtime 2, the highest outside voice a Retell or Vapi customer can choose, ranked 4th at 1119. Synthflow's Eleven v3 ranked 12th at 938.