The Vapi Alternative With
Predictable All-Inclusive Pricing
Phone Stack is a complete AI voice agent platform and a Vapi alternative for teams that want one predictable bill. Vapi charges a $0.05/minute orchestration base with STT, TTS, LLM, and telephony stacked on top ($0.07 to $0.25 per minute all-in), plus a $1,000/month HIPAA add-on. Phone Stack bundles everything into one flat monthly subscription from $69 per month with talk time included, with a HIPAA add-on available on Scale and Enterprise. Start free. 14 days, no card.
14 days free. No card needed to start.
Vapi pricing vs Phone Stack pricing
Vapi's headline number is a $0.05/minute orchestration base, but that's the platform fee, not the price of a call. Speech-to-text, text-to-speech, LLM tokens, and telephony each bill on top, so the true all-in cost lands anywhere from $0.07 to $0.25 per minute depending on the models you pick. Phone Stack charges one flat monthly subscription that covers the entire pipeline: voice AI, telephony, transcription, post-call analysis, CRM sync, and compliance tooling, with a block of talk time included.
Pricing verified 2026-06.
| Pricing | Phone Stack | Vapi |
|---|---|---|
| Headline price | From $69/mo flat, everything included | $0.05/min (orchestration only) |
| How the bill works | One subscription with 300 to 2,250 minutes included; $0.18 to $0.25 per extra minute by plan | $0.07 to $0.25 per minute all-in depending on STT, TTS, and LLM choices |
| HIPAA | Add-on available on Scale and Enterprise (signed BAA, contact us) | $1,000/mo add-on |
| Enterprise | From $1,799/mo, custom volume (from ~$21.6K/year) | $40K to $70K/year |
Worked example: 3,000 minutes per month
Phone Stack
- Scale plan: $399/mo subscription with 2,250 minutes included
- 750 extra minutes × $0.18 = $135, for a total of $534/mo, everything included
- The subscription is the bill. No component line items.
Vapi
- Orchestration base: 3,000 min × $0.05 = $150, before any STT, TTS, LLM, or telephony costs
- True all-in: 3,000 min × $0.07 to $0.25 = $210 to $750/mo depending on model choices
- Your bill moves whenever you change models, or when a provider changes theirs
To be fair: if you stay at the very bottom of Vapi's model range, Vapi can come in cheaper at this volume. The trade is predictability. Phone Stack's number doesn't move when you want better voices or a stronger model, and there's no engineering time spent assembling and maintaining the stack.
The HIPAA scenario
If your calls touch protected health information, Vapi's $1,000/month HIPAA add-on changes the math. At 3,000 minutes/month, Vapi runs $210 to $750 in usage plus $1,000 for HIPAA = $1,210 to $1,750/mo. Phone Stack's Scale plan covers the same 3,000 minutes for $534/mo, and HIPAA-eligible deployment with a signed BAA is available as an add-on on Scale and Enterprise: contact us to enable it and price it for your volume. You start from a base that is hundreds of dollars lower every month before the add-on even enters the comparison.
Full tier details are on our pricing page: Starter $69/mo (300 minutes included), Growth $199/mo (1,000 minutes), Scale $399/mo (2,250 minutes), and Enterprise from $1,799/mo with custom volume, contact sales.
Phone Stack vs Vapi: feature by feature
Vapi gives you voice infrastructure to build on. Phone Stack gives you a finished operation: campaign engine, supervision, and compliance included. (Claims verified 2026-06.)
| Feature | Phone Stack | Vapi |
|---|---|---|
| Pricing model | Flat plans from $69/mo, minutes included | Usage-based (STT + TTS + LLM separate) |
| Voice latency | ~320ms (native S2S) | ~400–700ms |
| Setup | Zero-code, chat training | API / developer required |
| Inbound calls | ||
| Outbound calls | ||
| Campaign engine | ||
| Listen Live | ||
| Barge In | ||
| HIPAA ready | ||
| TCPA compliance | ||
| CRM integrations | Native (HubSpot, GCal, 40+) | Via API |
| Voicemail detection | ||
| Free trial | 14 days free, no card | Free tier |
Everything Vapi leaves as an exercise for your team
Vapi is honest about what it is: middleware. It orchestrates the voice pipeline and leaves the application layer to you. That means building your own outbound dialer and queueing, voicemail handling, supervisor tooling, CRM writeback, and compliance workflows, then maintaining them.
- Built-in campaign engine with contact-list dispatch, voicemail detection, and post-call actions: the core of our AI-powered call center platform
- Listen Live and Barge In, so supervisors can monitor any call and take over instantly
- TCPA tooling: consent tracking, calling-window enforcement, recording disclosures, and DNC management
- ~320ms native speech-to-speech with no STT→LLM→TTS chain to tune. Every outbound voice agent ships with it by default
- Native CRM integrations (HubSpot, Google Calendar, 40+ tools) plus a REST API and webhooks when you do want code
Comparing more than one platform? See how Phone Stack stacks up against Retell, Bland, and Synthflow on the full comparison page.
When Vapi is the better choice
Vapi is a genuinely strong developer platform, and for some teams it's the right call. It has become the benchmark competitors measure themselves against for a reason. Pick Vapi over Phone Stack when:
- You're a developer building a fully custom voice stack and want maximum model flexibility
- You want to optimize every pipeline component yourself and can manage variable per-minute costs
If model-level control is your core requirement (swapping STT providers, A/B-testing TTS voices from different vendors, routing different calls to different LLMs), Vapi's flexible middleware approach is exactly what you want, and its $0.05/min orchestration base keeps the platform layer cheap. Phone Stack makes those choices for you in exchange for one flat bill, ~320ms latency, and a launch measured in minutes.
How to migrate from Vapi to Phone Stack
There's no pipeline to rebuild, only the agent's knowledge to carry over. Most teams complete the move within a day.
- 1
Export your Vapi assistant configs and prompts
Pull your assistant definitions, system prompts, and call flows from the Vapi dashboard or API. These are the source material for retraining; you won't need the pipeline code.
- 2
Recreate your agent via chat training
Phone Stack has no assistant API to configure. Paste your prompts and describe your call goals in the chat trainer; it works like onboarding an employee. Most agents are retrained in 15 to 30 minutes.
- 3
Port or provision phone numbers
Port your existing numbers or buy new ones inside Phone Stack. Inbound routing and outbound caller ID are configured from the dashboard, not via API calls.
- 4
Test during your 14-day free trial
Every account starts with a 14-day free trial, no card needed. Run live test calls, listen via Listen Live, and use Barge In to take over mid-call while you tune the agent.
- 5
Go live and retire the component stack
Launch your campaigns or flip inbound routing over. There are no STT, TTS, or LLM vendor accounts to keep paying; one subscription covers the whole pipeline.
Vapi Alternative FAQs
Common questions from teams evaluating Vapi and Phone Stack.
One flat bill. No stack to assemble.
Train your agent via chat and hear the ~320ms difference yourself. Start free. 14 days, no card.