DiaVoice vs OpenPhone — A Real Business Phone System vs a Smart Number App
OpenPhone is great for solo operators who need a second number. DiaVoice is a full cloud PBX with AI receptionist, eFax, and enterprise-grade call handling — built for businesses that are serious about growth.
DiaVoice
- ✓ Full cloud PBX — ring groups, queues, IVR, conferencing
- ✓ AI receptionist — full conversational (from $15/mo)
- ✓ Call recording included on every plan
- ✓ DiaFax HIPAA-ready eFax (from $34/mo)
- ✓ Built to scale from 2 to 200+ employees
- ✓ DiaVoice Go mobile app — free
- ✓ No contracts — $20/user/month
OpenPhone
- • Phone number app — not a full PBX
- • Basic auto-attendant only
- • Call recording only on Business plan ($23/user/mo)
- • No eFax service
- • Best for solopreneurs and very small teams
- • Good mobile app
- • Starting at $15/user/month (limited)
The Honest Breakdown
What OpenPhone Actually Is
OpenPhone is a smart phone number app. It gives you a business number on your personal device with shared inboxes and basic call handling. It is clean, simple, and works well for what it is — but it is not a PBX. There are no ring groups, no call queues, no real IVR, no conference bridges. If you are a freelancer or solo operator who needs a professional second number, OpenPhone is a solid choice. If you are running a business with multiple employees and need real phone system features, you will outgrow it fast.
Pricing
OpenPhone starts at $15/user/month on their Starter plan. But that plan lacks call recording, ring groups (Business plan feature), and advanced call routing. To get features that DiaVoice includes by default, you need OpenPhone Business at $23/user/month — and even then, you still do not get full PBX capabilities.
DiaVoice DiaPBX is $20/user/month with every PBX feature included — ring groups, call queues, IVR, conferencing, call recording. No tiers to compare, no features locked behind higher plans.
AI Receptionist
OpenPhone offers a basic auto-attendant — standard menu routing for incoming calls. DiaVoice AI is a full conversational AI receptionist that understands natural language, answers questions about your business, takes detailed messages, and routes calls intelligently. It is the difference between "Press 1 for sales" and a real conversation — starting at $15/month.
PBX Features
This is the fundamental difference. OpenPhone is not a PBX. It does not offer ring groups, call queues, conference bridges, or multi-level IVR menus on its base plan. DiaVoice is a full cloud PBX built on enterprise-grade infrastructure — DiaPBX gives you everything from extensions and voicemail to ring groups, call queues, IVR, conference calling, and call recording. All included at $20/user/month.
eFax
OpenPhone does not offer eFax. If your business needs faxing — healthcare, legal, real estate — you need a separate vendor. DiaFax is DiaVoice's HIPAA-ready cloud fax solution starting at $34/month, integrated with your phone system. One provider, one bill.
Who Grows Out of OpenPhone
We hear this story regularly: a business starts with OpenPhone at 1-2 people, grows to 3-4 employees, and suddenly needs ring groups, call queues, a real IVR, or call recording. OpenPhone was not built for that. If you are in a regulated industry (healthcare, legal, finance) or need enterprise-grade call handling, the limitations show up even sooner. DiaVoice is the phone system you grow into, not out of.
Feature-by-Feature Comparison
| Feature | DiaVoice | OpenPhone |
|---|---|---|
| Starting price | $20/user/mo | $15/user/mo (limited) |
| Full PBX features | Yes — all included | No — phone number app |
| AI receptionist | Yes — full conversational AI | Basic auto-attendant |
| Ring groups / IVR | Yes — all plans | Business plan only ($23/user/mo) |
| eFax | Yes — DiaFax HIPAA-ready | No |
| Call recording | ✓ Included | Business plan only ($23/user/mo) |
| Mobile app | ✓ DiaVoice Go (free, no app store) | ✓ |
| Contract required | No | No |
| Built for growth | Yes — 2 to 200+ employees | Solopreneur / very small teams |
Who Each Is Better For
OpenPhone might be better if you...
- • Are a solopreneur or freelancer who needs a clean second number
- • Want the simplest possible phone app with shared inboxes
DiaVoice is better if you...
- ✓ Have 2 or more employees and need real PBX features
- ✓ Are in a regulated industry (healthcare, legal, finance)
- ✓ Need a real AI receptionist, not just a menu
- ✓ Need HIPAA-ready eFax
- ✓ Are serious about professionalism at scale
Frequently Asked Questions
Is DiaVoice more expensive than OpenPhone?▾
DiaVoice is $20/user/month and OpenPhone starts at $15/user/month. But DiaVoice includes full PBX features — ring groups, call queues, IVR, conferencing, call recording — all included. OpenPhone locks many features behind their $23/user/month Business plan. For what you actually get, DiaVoice is the better value.
Can I keep my numbers if I switch from OpenPhone?▾
Yes. We handle the entire porting process. It typically takes 7-10 business days, and there is no downtime during the transfer.
Does DiaVoice have a better AI receptionist than OpenPhone?▾
Significantly. OpenPhone offers a basic auto-attendant. DiaVoice AI is a full conversational AI receptionist that understands natural language, answers questions about your business, takes detailed messages, and routes calls intelligently — starting at $15/month.
Does OpenPhone have eFax?▾
No. OpenPhone does not offer eFax. DiaVoice offers DiaFax, a HIPAA-ready cloud fax solution starting at $34/month, integrated with your phone system.
Is DiaVoice good for businesses outgrowing OpenPhone?▾
Yes — this is actually one of the most common reasons businesses come to DiaVoice. When you hit 3-4 employees and need ring groups, call queues, IVR, and AI call handling, OpenPhone's limitations become obvious. DiaVoice gives you a full business phone system that scales with you.
Ready to Graduate to a Real Business Phone System?
Call our demo line and hear DiaVoice AI in action — no signup, no pressure.