Short answer
Smith.ai bills per call and offers both an AI receptionist (free tier, Pro from $150 a month) and live humans (from $300 a month). Ruby uses live US-based humans billed by minutes, from $250 a month for 50 minutes, and lists HIPAA-compliant services. A managed AI employee like Oraculo is a third option when you need more than call answering.
Two answering services, two billing systems
Smith.ai and Ruby both answer calls for small businesses, and both put people in front of the phone. The reason they feel different on an invoice is how they count. Smith.ai bills per call. Ruby bills per minute (or per chat). That one difference changes which service is cheaper for your kind of caller.
This comparison uses published prices as of October 2026. It adds a third column for an AI employee, because a fair share of owners comparing these two are really asking whether they need a receptionist at all.
The three-way table
| Smith.ai | Ruby | AI employee (Oraculo) | |
|---|---|---|---|
| Who answers | AI receptionist or live humans | Live US-based humans | AI employee |
| Billing | Per call, not per minute | Per minutes (or chats) | Hours of work; calls $0.19/minute |
| Entry price | AI free for 25 real calls; Pro from $150/month. Human from $300/month (30 calls) | $250/month for 50 minutes | Starter $12/hour, 6 hours/week minimum (about $312/month) |
| Larger plans | Human Basic $810 (90 calls); Pro $2,100 (300 calls) | 100 min $395; 200 min $720; 500 min $1,725 | Business $8/hour, 43 hours/week (about $1,500/month) |
| Overage | AI Pro $2.17-$2.50/call; human Starter $11.50/call | Not stated on the page | Billed by published task-time chart |
| Chat | Chat and SMS/Slack notifications mentioned as add-ons | Live chat plans from $143/month (10 chats) | Text, WhatsApp, Slack, Telegram, email, app |
| Spanish | Spanish line add-on $1.00/call | Spanish and bilingual handling | Bilingual English and Spanish use case |
| HIPAA | Not confirmed on pricing pages | Lists HIPAA-compliant services | Not a medical product |
| Beyond calls | Not confirmed | Scheduling, payment collection, lead qualification, intake | Follow-up, invoices, social, website, email, team tracking |
| Guarantee | 30-day money-back on human plans | Not stated in our sources | 30-day money-back |
When per-call beats per-minute, and the reverse
A rule of thumb, which is arithmetic rather than a claim about either company: per-minute pricing rewards brief calls, because a 90-second call uses little of your allowance. Per-call pricing rewards long calls, because a 15-minute conversation costs the same as a 90-second one.
- Short, frequent calls (hours, directions, is-this-the-right-number): per-minute billing tends to suit these, since each call uses few minutes. Smith.ai's per-call rate is easy to forecast, but the free AI tier caps at 25 real calls.
- Long intake calls (a legal consult, an insurance claim): a per-call price can be a bargain, because the call length does not matter. The same calls can burn through a minute allowance quickly.
- Unpredictable spikes: both pricing styles have overage. Smith.ai publishes overage on its AI Pro and human Starter tiers. Ruby's page does not state overage, so ask.
Pull a month of your phone log, count the calls and the minutes, and price both. It takes ten minutes and is more reliable than any rule of thumb. Also note how many calls are spam or wrong numbers: Smith.ai says spam is not charged on its human plans, and Ruby's page does not say either way.
What each is genuinely good at
- Smith.ai: flexibility. You can start free with AI, move up to Pro, or switch to humans, month to month with 30 days notice on AI plans. Spam calls are not charged on human plans.
- Ruby: consistency of voice. Live US-based receptionists, 24/7 including holidays, with HIPAA-compliant services listed, which matters for practices.
- Both: real people available at night, on weekends and on holidays, and both do scheduling and lead intake in some form.
For the AI-versus-human decision on its own, see AI answering service vs human answering service.
Where an AI employee fits
Neither service claims to do your follow-up, invoicing, social posts or staff tracking. An AI employee does, and answers the phone too. Oraculo answers and places calls on your line 24/7, replies to every lead in minutes, confirms appointments, sends invoices and tracks your team. You can message it on WhatsApp, iMessage, Slack or Telegram, and an engineer sets it up with you in four 1-hour Zoom sessions.
Tradeoffs: no live human voice, no HIPAA claim, and a Starter minimum of about $312 a month. See Oraculo vs Smith.ai and Oraculo vs Ruby Receptionists.
Which to pick
| If you... | Pick |
|---|---|
| Want to try call answering for free | Smith.ai AI plan |
| Want predictable per-call pricing with humans available | Smith.ai human plans |
| Need a consistent human voice and HIPAA-ready service | Ruby |
| Have many short calls and tight budgets | Compare both on your phone log |
| Need phone, follow-up and back-office in one | AI employee (Oraculo) |
Oraculo's pricing: Starter $12 per hour (about $312 a month), Business $8 per hour (about $1,500 a month), $499 setup, 30-day money-back guarantee. Book a 20-minute demo to see your phone log handled.
Key takeaway
Smith.ai and Ruby are both solid answering services that differ mainly in billing and HIPAA. Price your actual call log, and add an AI employee to the shortlist if the work after the call is the real bottleneck.
Frequently asked questions
Is Smith.ai or Ruby cheaper?
It depends on call length and volume. Smith.ai bills per call, with human plans from $300 a month for 30 calls. Ruby bills by minutes, from $250 a month for 50 minutes. Price your own phone log both ways.
Does Ruby use real people?
Yes. Ruby uses live, US-based human receptionists, including after hours, weekends and holidays. Smith.ai offers both live humans and an AI receptionist.
Which is HIPAA-ready?
Ruby lists HIPAA-compliant services for receptionist and chat plans. Smith.ai's pricing pages do not mention HIPAA, so it is not confirmed. Ask each vendor directly and get it in writing.
Can an AI employee replace both?
For many service businesses, yes, because it answers calls and also handles follow-up and back-office work. If callers need a live human every time, keep a human service.
Do I need a contract?
Smith.ai's AI plans are month-to-month with 30 days notice, and human plans have a 10% discount for a 12-month term. Ruby's pricing page does not state contract terms, so ask.