Power dialer vs predictive dialer
A power dialer calls the next number on your list the moment a rep is free, one line per rep. It's simple and it never drops a call, but your rep hears every ring and every voicemail on the way to a live person.
A predictive dialer doesn't wait for a free rep. It dials several numbers per rep at once and uses live stats to time it so the next person who picks up connects right as a rep finishes a call. Reps get more conversations an hour, as long as someone keeps it tuned.
How a power dialer works
A rep finishes a call, the dialer calls the next number, and the rep listens to it ring. That's the whole loop. One rep, one line. GoHighLevel's built-in Power Dialer works this way, and so do the dialers in plenty of other sales tools.
There's nothing to set up or tune. And since the rep is already on the line when someone answers, nobody picks up to dead air. Honestly, for one or two reps working warm leads, that's all you need.
The problem shows up on cold lists. Most calls ring out or hit voicemail, and your rep sits through every one of them. (Some tools sell a multi-line power dialer that calls a few numbers at once. That behaves more like a parallel dialer, covered below.)
How a predictive dialer works
It works off a forecast. Every few seconds it checks how many people are answering and how long calls are running, then decides how many lines to dial for each ready rep. That number is the dial level. The ringing and the dead numbers stay with the dialer, so reps spend their time on people who picked up.
It can get the timing wrong, though. If more people answer than there are free reps, someone says hello to silence. That's a dropped call, and in the US the FTC caps them at 3% of calls answered by a person, per campaign, over each 30-day period. So a predictive dialer is always trading rep wait time against that limit. The full mechanics are in what is a predictive dialer?
What about parallel dialers?
A parallel dialer calls a set number of lines per rep at once and connects whoever answers first. That cuts down the waiting, but nothing is being forecast. Most are sold to B2B sales teams calling business lines.
Side by side
The three split on two things: when they dial, and how much attention they need.
| Power | Parallel | Predictive | |
|---|---|---|---|
| When it dials | When a rep is free | When a rep is free, on several lines | Ahead of the reps, from a forecast |
| Lines per rep | Usually 1 | A set number | Changes all day |
| Who sits through the rings | The rep | The rep, less often | The dialer |
| Dropped calls | None at one line | Possible | Kept under a ceiling |
| Upkeep | None | Low | Constant tuning |
| Good fit | A rep or two, warm leads | B2B teams | Several reps, cold lists |
Why most teams stick with a power dialer
Because a predictive dialer only performs while somebody keeps an eye on it.
The right dial level moves all day. It changes when reps log in or go on break, when a list goes from fresh leads to recycled ones, and when answer rates shift between morning and afternoon. Each campaign behaves a little differently, too. Then there are the caller IDs. Once a number gets tagged "Spam Likely," people stop answering it, and no pacing setting brings them back.
So floors that want predictive dialing usually end up doing one of three things:
- Running ViciDial in-house. It's open source, extraordinarily powerful and highly configurable, with over 24,000 installs in more than 100 countries by its own count. It also means Linux servers, the Asterisk phone system, carrier trunks, dated admin screens and somebody on payroll who knows which of the hundreds of settings to touch.
- Renting an enterprise contact center suite. The servers go away and the screens look better, but these are built for big contact centers, usually sold per seat on annual contracts, and they still need a trained admin to run campaigns.
- Settling for a power dialer. Nothing to tune, and reps go back to listening to the phone ring.
Where Hershel comes in
Hershel is a predictive dialer built from ViciDial, with AI doing the tuning a person used to do.
I came at this from the floor side. I run outbound solar appointment setting floors in Texas and Florida, and ViciDial was the most powerful dialer I could find. It was also the most work to keep running. So Hershel kept the predictive engine, along with the campaigns, lists and statuses floors already know, and rebuilt everything around it: its own rep console, its own manager screens, and AI that runs dial pace, caller IDs and call notes.
What the AI handles
- Dialler Manager checks each campaign about every 10 seconds (drop rate, rep wait time, pause time, leads left to dial) and moves the dial level to keep reps talking while drops stay under the ceiling you set.
- The Shield watches every outbound number for spam flags and carrier refusals. When a number burns, it buys a clean one, swaps it into rotation and tells a manager.
- Hershel works with your own Twilio or Telnyx account, and it catches carrier-side refusals (channel limits, calls per second) that normal call logs don't show.
- Closable transcribes every appointment-set call and posts a closer brief to the contact in GoHighLevel before the appointment.
It's all fully managed, 24/7, with a dedicated dialer server for each client. There's more on this in what is an AI dialer?
Frequently asked questions
What's the difference between a power dialer and a predictive dialer?
A power dialer waits for a rep to be free, then calls one number. A predictive dialer calls several numbers ahead of time and forecasts when reps will be free, so reps spend less of the hour listening to phones ring.
Can a power dialer drop calls?
Not at one line per rep, since the rep is already on the line when someone answers. Multi-line power dialers can, when more people pick up than there are free reps.
What is a parallel dialer?
It calls a set number of lines per rep at the same time and connects whoever answers first. It cuts waiting like a predictive dialer, but it doesn't forecast. Most parallel dialers are sold to B2B sales teams.
Can AI run a predictive dialer?
Yes. Hershel's AI checks each campaign about every 10 seconds and adjusts the dial level against drop rate and rep wait time, inside the ceiling the floor sets. It also handles caller ID health and closer briefs as a fully managed service.
See Hershel run a live floor
Predictive dialing, with AI handling the tuning around the clock.
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