14 Best Sales Dialer Software for High-Volume Outbound Calling in 2025

Although the “definition” of a sales dialer software remains more or less the same, it’s the experience that counts. 

This post is all about filling you in on some of the best sales dialer software out there. Keep in mind that the term: best sales dialer tool or software is general. We have summarized different types of dialing solutions, such as an auto dialer for sales teams, sales dialer analytics tools, different parallel dialers, power dialers, and vice versa.

This was done intentionally because, unlike other online listicles, which are dedicated to only one type of resource, subject to the content category, our plan was to sum everything up in one place.

So, let’s see what everyone in the outbound sales industry is excited about.

What Is a Sales Dialer Software?

Although we have talked about sales dialers over the past couple of months in detail, but just to sum it for you from a definition point of view, here’s a quick rundown on what they’re all about.

A sales dialer is any software that helps you, or your sales teams to make calls to prospects. Case in point; these are all outbound calls solely intended for the purpose of acquiring new leads or converting them into paying customers.

Furthermore, sales dialers are of many types. You have auto dialers and power dialers that automatically call numbers in a single line format. It means that only one person is called at a time. As soon as the call drops, the sales rep is connected to the next person. 

The best type of sales dialers are the ones that come with parallel dialing mode. This feature, although slightly expensive, enables multi-line dialing in real time. Basically, you get by with better outreach, a higher call volume, and more coverage as compared to the traditional power dialing experience. 

Why Trust Us

Choosing the right sales dialer software isn’t just about comparing feature lists. It’s about understanding how these tools perform in real outbound environments, where connect rates, rep productivity, and call quality directly impact revenue.

At Trellus, we work with hundreds of outbound teams, founders, and sales managers every day. We understand what actually moves the needle because we build a sales-first platform ourselves, and we consistently hear from SDR leaders about what works and what doesn’t. Our insights come from:

• Firsthand experience working with real sales teams using dialers daily
• Direct conversations with SDRs, BDRs, founders, and agencies managing high-volume outbound
• Continuous benchmarking against industry-leading dialers and call productivity data
• Hands-on testing of integrations, dialer performance, speed, and usability

Unlike generic listicles that simply pull descriptions from vendor websites, our recommendations reflect practical, day-to-day sales execution realities: connect rates, call clarity, CRM integration stability, analytics depth, and total cost of ownership.

Our Methodology: How We Selected the Best Sales Dialer Software

To ensure fairness and accuracy, each platform in this list was evaluated using a multi-step criteria-based framework. Here's how we selected and ranked the tools:

1. Performance & Connect Rate Potential

We prioritized dialers that support:

• High-volume outbound calling
• Parallel/Power dialing modes
• Reliable carrier routing
• Low latency + clean audio
• Spam remediation and detection
  

Any platform with inconsistent call performance or unreliable routing was not included.

2. Feature Depth for Modern Outbound Teams

We evaluated tools on their ability to support fast-moving SDR workflows, including:

• Auto/power/predictive dialing, while parallel dialing being the most important aspect
• AI call insights or coaching
• Call recording + transcription
• Live monitoring, whispering, and barging
• Local presence/number acquisition
• Compliance safeguards

Platforms offering only basic VoIP capabilities were excluded unless they served a specific niche effectively (e.g., support-heavy systems like LiveAgent).

3. Integration Quality & CRM Compatibility

We assessed how well each solution integrates with major CRMs and sales engagement tools, including:

• HubSpot
• Salesforce
• Apollo
• Salesloft
• Outreach
• Pipedrive
• Zoho
• Many others

Stability, two-way sync, click-to-call functionality, data mapping, and workflow automation were key scoring factors.

4. Real-World Usability & Onboarding Experience

We evaluated:

• UI/UX simplicity
• Learning curve
• Ease of onboarding SDR teams
• How fast a team can start making calls

Platforms with complex or outdated interfaces did not score high unless their functionality significantly outweighed usability limitations.

Best Sales Dialer Software for Outbound Calling Purposes

1. Trellus.ai - Overall No.1 Solution For Sales First Platforms

Starting off with Trellus as one of the best solutions to date, we’d like to state that our platform is more of a lightweight purpose built resource for different types of sales businesses.

And for that to happen, we have introduced tons of user-requested features, besides being on the lookout for releasing more of those as time goes on. 

Why I Picked This Tool

Trellus is the only platform in this list built specifically for sales-first teams and founders, and not just for call centers. 

The online platform offers parallel dialing, AI coaching, LinkedIn Superhuman, and CRM-native workflows in one lightweight environment. It’s purpose-built for high-volume outbound and SDR productivity, which is why it ranks #1.

Special Standout Features

• Embedded parallel dialer for maximum connect rate
• Real-time AI call coaching
• AI practice calls based on past conversations
• LinkedIn Superhuman for social outreach
• Spam remediation + number acquisition intelligence
• Leaderboards with custom timeframes
• Research automation to reduce SDR workload

Integrations

• HubSpot
• Salesforce
• Salesloft
• Apollo
• Outreach
• ZoomInfo
• Orum
• Kixie
• Salesfinity
  …and many others.

Pros:

• Best all-in-one sales execution environment
• Strongest CRM-native experience
• Parallel dialing included (rare for the price)
• Deep AI support for coaching & practice
• Ideal for SDR teams and solo founders

So, if you’re managing a sales business or as part of an SDR/BDR team, you have different sales calling and outreach solutions at your disposal. 

• Integration and Centralization Aspect

Trellus integrates easily with your CRM. 

That means that you no longer have to switch between your CRM’s interface and Trellus’s UI to manage the same workflow. Plus, our integration support for different platforms is always increasing, alongside our core focus on making the overall user experience as seamless as possible. 

Some of the popular CRMs that we integrate with are: Salesloft, Apollo, Outreach, HubSpot, ZoomInfo, Salesfinity, etc. The full list of integrations can be seen on our page. 

• Embedded Parallel Dialing

Ensuring the highest connect rate comes through a bunch of things. 

You need to make sure that a higher call volume aspect is there. This is only possible if your sales reps are calling as many leads as possible. Of course, you can use the native power dailing experience, but to take it a step further, we also offer an embedded parallel dialing system.

Our parallel dialer is not only cost effective, but enables sales teams to call multiple contacts at the same time, and IN REAL TIME. Whoever on the other side picks up the call is connected to the corresponding salesperson. 

Other than that, we have programmatically introduced a system that detects your leads acquisition rate based on the type of numbers and businesses that you usually call. And of course, it enhances the connect rate drastically. 

• LinkedIn SuperHuman

Who says that outreach has to be limited to cold and warm calls only? 

Yes, there are platforms focused on offering different features within the calling aspect of your sales business workflow, but we also have other modes of reaching out to prospects, such as LinkedIn Superhuman. 

Your sales team can connect with different people over LinkedIn - and that too, over a consolidated communication experience where messages can be grouped by high to low priority leads. 

And of course, it helps with the research aspect too. The better the research is, the overall chances of lead conversions are higher.

• Real Time AI Call Coaching

Our platform also comes with a real time call coaching experience. 

How does it work?

We have a built-in AI powered conversation intelligence system that recognizes ongoing call patterns and reduces any communication challenges on your reps’ end through in-call cues. 

If your sales rep is a little weak on answering a cold call objection, the cue can nudge them in the right direction, causing the SDR to respond in a better way that fulfills a lead’s requirements in terms of Q&A session.

• AI Practice Calls

What if your sales reps need a little bit of extra handholding without the involvement of a sales call coach?

For that purpose, Trellus comes with a feature that allows sales representatives to deploy practice call sessions against AI bots that act as a prospect. The best part of this whole exercise is that these practice sessions are based on real-life calls that happened before in your company’s sales calling history. 

Plus, by doing so, it saves up time on the real-life call coaching aspect because sometimes it’s not possible to book up training sessions. And if a coach isn’t available from within the company, then you’re looking at hiring someone from outside, and it also calls for spending extra money on these training workshops.

So there’s that.

• Built for the Frontline, and for Founders, Too

Trellus is equally powerful for SDR teams and solo founders managing their own pipeline. If you’re an early-stage founder making your own calls, Trellus helps you maintain calling discipline, organize your data, and handle consistent outreach without the overwhelm of juggling tools.

It replaces fragmented workflows with one environment built for sales execution.

Who should consider Trellus:

• SDR and BDR teams making hundreds of calls per day
• Sales managers who want insight without micromanagement
• Agencies running outbound campaigns for clients
• Founders still handling outbound calls themselves

2. RingCentral

We have mentioned RingCentral a couple of times before. 

Owing to its popularity, the platform has a decent following from within the sales industry these days. 

The main thing to keep in mind is that RingCentral is essentially a software solution for call center businesses. Yes, it can be used for general category outbound sales calls through SDR teams, but the bulk of the program’s scope leans on call and contact center solutions out there.

For that purpose, they’ve got automatic call distribution, interactive voice response agent tools for real time guidance, and vice versa. You can look at the full list of their value offerings at the company’s official website. 

RingCentral is one of the most established VoIP + call center solutions and made this list because of its reliability, global telecom infrastructure, and suitability for hybrid teams handling both inbound and outbound calls.

Standout Features

• Automatic call distribution (ACD)
• Interactive voice response (IVR)
• Real-time agent guidance
• Analytics dashboard
• Business phone + call center suite combined

Integrations

• Salesforce
• HubSpot
• Zendesk
• Microsoft Teams
• Google Workspace

Pros & Cons

Pros:

• Extremely reliable infrastructure
• Great for call centers with complex routing
• Large integration ecosystem

Cons:
– Not purpose-built for SDR teams
– Heavy interface compared to lightweight dialers

3. CloudTalk

Up next on our best sales dialer software recommendations list, we’ve got CloudTalk. 

Why I Picked This Tool

CloudTalk is distinct in the sense that it’s a tool specifically made for remote sales teams.

With calling capabilities in 140+ countries and a strong focus on sales enablement, it’s ideal for distributed SDR operations.

Standout Features

• Power dialer
• Global calling support in 140+ countries
• Call monitoring + whispering
• Skill-based routing
• Analytics & performance dashboards

Integrations

• Zoho
• HubSpot
• Salesforce
• Freshsales
• Zendesk
• ActiveCampaign

Pros & Cons

Pros:

• Excellent call quality worldwide
• Flexible workflows for remote teams
• Easy CRM integrations

Cons:
– Pricing increases as you scale
– Some advanced features require higher-tier plans

It’s a robust software with a focus on sales enablement for remote outbound sales teams. Features-wise, we are looking at different solutions for both call centers and B2B sales calling businesses. Among other things, the best part about CloudTalk is that you can call prospects and contacts in over 140 countries.

The program also integrates with different CRMs/ such platforms as: Zoho CRM, Copper, ActiveCampaign, Freshsales, Zendesk, Hubspot, Salesforce (*being one of the most popular and in demand platforms), Gorgias, etc.4 

4. Ringover

As evident from its name, Ringover is another solution that tops our list of the best auto dialer software and power dialer tools. 

Why I Picked This Tool

Ringover is budget-friendly and easy to deploy, making it great for small and mid-sized outbound teams that want a simple, clean calling workflow.

Standout Features

• Power dialing
• Business phone system
• 7-day free trial
• Call recording + monitoring
• SMS + WhatsApp support
  

Integrations

• Salesforce
• HubSpot
• Pipedrive
• Zoho
• Microsoft Teams

Pros & Cons

Pros:

• Affordable
• Straightforward onboarding
• Good for SMBs

Cons:
– Not built for extremely high call volume
– Requires physical equipment in some setups

On the upside, they’re offering a 7-day cost-free trial package for you to evaluate the program’s features. Paid plan starts at $21 per user/ per month. But that’s not the main reason we picked up this platform over other solutions out there.

With Ringover, you get a dedicated business phone solution that can integrate with your CRM due to extensive integration support. It’s a program well-suited for small and medium scale outbound sales businesses, ensuring that the workflow doesn’t exceed the budget limits set by your organization.

The platform has a minimum learning curve. This way, you won’t have to appoint a technology champion to onboard and train the entire sales team over subsequent weeks. However, it does require specific equipment for better call quality. 

5. Nextiva

Nextiva is extremely popular and widely recognized as a robust sales dialer software. Part of the popularity factor is their regular content updates on YouTube and such other streaming platforms. Jessica Hord is pretty popular as she not only hosts most of the company’s programs and videos, but she’s also recognized as more or less of a celebrity among Nextiva’s user base.

Why I Picked This Tool

Nextiva combines strong dialer capabilities with one of the best support and content ecosystems. It's widely trusted and feature-rich for both inbound and outbound operations.

Standout Features

• Automated outbound campaigns
• AI-powered call insights
• Real-time call + network status
• Call queues + routing
• Voicemail drops
  

Integrations

• HubSpot
• Salesforce
• Zendesk
• Microsoft Dynamics
  

Pros & Cons

Pros:

• Robust feature set
• Excellent support resources
• Great analytics

Cons:
– Better suited for hybrid call environments
– Can feel overwhelming for small teams

With respect to features, we are looking at automated outbound campaign management, AI powered features, real time call and network status updates, a proactive notification system, and stuff like that.

Plus, they also have integration support for popular CRMs, so that all your work is managed from within the same interface.

6. DialPad

Dialpad is another super affordable solution as a sales calling software for outbound sales businesses. 

Why I Picked This Tool

Dialpad is one of the most affordable AI-enabled dialer solutions, making it perfect for startups and lean outbound teams wanting AI insights without enterprise-level pricing.

Standout Features

• AI-powered call transcription
• Real-time call insights
• Video calling
• Call recording
• HIPAA & SOC2 compliance

Integrations

• HubSpot
• Salesforce
• Outreach
• Zendesk

Pros & Cons

Pros:

• Very affordable
• Lightweight + easy to adopt
• Strong AI transcription

Cons:
– Limited advanced dialing modes
– Not ideal for large SDR orgs

They offer a focus on high interaction user experience through features, such as AI driven call insights, call recording, HIPAA and SOC2 compliance, VM drops, video communication, etc. 

7. AirCall

If you’re active in the online sales industry, you might be familiar with AirCall. 

Why I Picked This Tool

Aircall is one of the most popular SDR-friendly dialers, known for its clean interface and reliable call experience. It’s widely used in SaaS and B2B teams.

Standout Features

• Call whisper + call monitoring
• Warm transfers
• Power dialing
• Call tagging + analytics
• Team activity dashboard

Integrations

• HubSpot
• Salesforce
• Intercom
• Pipedrive
• Slack

Pros & Cons

Pros:

• Very intuitive interface
• Strong analytics
• Great for SaaS outbound teams

Cons:
– Pricing can scale quickly
– Local presence options vary by region

It’s a B2B and outbound call center dialing solution with tons of features that offer a wholesome sales and outreach experience to worldwide businesses. 

Aircall comes with traditional tools that you would normally expect from outbound sales dialer software, and some additional perks such as real time call whispering, warm call transfer capabilities, call analytics and insights. 

For a full list of their overall value offering, feel free to visit AirCall’s official website.

8. CallHippo

Up next we’ve got CallHippo.

Why I Picked This Tool

CallHippo offers one of the lowest-cost power dialers on the market, ideal for small businesses and early-stage SDR teams on a tight budget.

Standout Features

• Power dialer
• Automatic machine detection
• Call forwarding
• Call queuing

Integrations

• Zoho
• HubSpot
• Pipedrive
• Freshsales

Pros & Cons

Pros:

• Low cost
• Simple and easy to use
• Fast setup

Cons:
– Not ideal for large teams
– Limited advanced analytics

One of the best features of this platform, besides an all time low price factor, is its native power dialer. Since CallHippo is more of a small to medium business-friendly solution, the platform’s power dialer focuses on back to back single line dialing for sales reps who are on a time crunch.

They also have an automatic machine detection system, ensuring that your sales reps don’t run into auto responders or voice bots. Its pure focus is on maximizing call connect rate and quality with an equal number of opportunities for all kinds of sales reps in the company.

9. JustCall

JustCall is a popular go-to solution for sales businesses for a variety of reasons.

For starters, they have a 14-day trial window, which is more than enough for first-timers to evaluate the software features against the business requirements. 

JustCall is a versatile option combining dialing with strong AI-assisted features for training and real-time coaching, making it useful for sales managers.

Standout Features

• Call whispering
• Live call monitoring
• 14-day trial
• AI post-call summaries
• Call recording

Integrations

• HubSpot
• Salesforce
• Zoho
• Freshdesk

Pros & Cons

Pros:

• Excellent call coaching tools
• Easy for managers to monitor reps
• Solid analytics

Cons:
– Can be expensive at scale
– UI can feel cluttered for new users

Speaking of features, we are looking at advanced call analytics for sales reps and, more importantly, sales manager.s You get an AI powered whisper system. If you’re a sales manager who dabbles in live call monitoring and listening, the whisper system will let you send cues to your sales rep while he or she is engaged with a potential big ticket prospect.

Overall, it’s a decent solution that could easily suit multi-sized sales and contact center platforms. You should give it a try if you aren’t satisfied with other sales callers that you have tried before.

10. Zoho Voice

Zoho itself is a CRM and analytics platform for businesses that count on keeping tabs on sales conversions, sales volume, numbers and metrics sort of stuff. 

So, it doesn’t necessarily have to be your only go-to solution for the purpose of making outbound sales calls. But, if your business involves the SaaS niche with an existing customer base and you’re already using Zoho CRM, then the Zoho Voice platform can come in handy as a telephony solution that integrates with your existing tech stack.

Why I Picked This Tool

Zoho Voice is ideal for teams already using Zoho CRM. It’s a practical way to consolidate calling workflows inside an existing SaaS ecosystem.

Standout Features

• Advanced dialer mode
• Call automation
• Call masking + forwarding
• Campaign management
• Cloud telephony

Integrations

• Zoho CRM
• Zoho Desk
• Zoho SalesIQ

Pros & Cons

Pros:

• Perfect for Zoho-first stacks
• Affordable
• Smooth ecosystem experience

Cons:
– Limited value outside Zoho
– Missing advanced dialing modes like parallel dialing

It’s an AIO sales call solution with a focus on advanced dialer mode, different automation features, sales campaign management, and 24/7 cloud based telephony service.

11. Convoso

Convoso is not only part of our integrations page, but it is also recommended as a dialing solution for sales businesses.

Why I Picked This Tool

Convoso is a top pick for high-volume dialing with AI-based optimization. It specializes in industries where connect rate and efficiency are mission-critical.

Standout Features

• AI-driven dialing and routing
• Local caller ID management
• Compliance automation
• Performance dashboards
• Multi-line dialing

Integrations

• Salesforce
• HubSpot
• Zoho
• Velocify

Pros & Cons

Pros:

• Extremely powerful for high volume
• Excellent connect-rate optimization
• Industry-specific workflows

Cons:
– Not built for small teams
– Higher price point

In essence, it’s a digital AI-focused calling solution that reportedly boosts sales teams’ performance and overall efficiency. Speaking of artificial intelligence, Convoso comes with AI-driven dialing optimization that focuses on maximizing your connect rate. 

It’s a solution for you if your business is in finance, real estate, home services, or the insurance sector. 

12. Five9

This one is an AIO outbound sales dialer software that enables agents to engage with customers. Alongside those calls, you will have plenty of different opportunities to create effective relationships with prospects, turning them into repeat business opportunities.

Why I Picked This Tool

Five9 is one of the most established enterprise-level outbound dialer systems. 

This sales calling app is built for organizations that need full-scale call center functionality.

Standout Features

• Predictive dialing
• Power dialing
• Call archiving
• CRM analytics
• Call scripting

Integrations

• Salesforce
• Oracle
• Microsoft Dynamics
• Zendesk

Pros & Cons

Pros:

• Very scalable
• Enterprise-grade features
• Trusted in large orgs

Cons:
– Expensive
– Overkill for small outbound teams

Five9 has high-demand features, such as call recording, call analytics, power dialer software, call archiving, and integrations support.

13. Novocall

We are recommending Novocall as a sales dialer as part of dedicated solutions for large-scale and enterprise sales businesses. 

Novocall is built for enterprise-grade outbound calling workflows that require call blasts, advanced analytics, and high-volume automation.

Standout Features

• Auto dialer
• Call blast
• Visual call journeys
• Call scheduling
• Contact list management

Integrations

• HubSpot
• Pipedrive
• Salesforce

Pros & Cons

Pros:

• Great for large-scale call campaigns
• Strong analytics
• Enterprise reliability

Cons:
– More expensive than competitors
– Not suitable for SMBs

Since the program is slightly expensive as compared to other software on our list, Novocall isn’t recommended for small and medium-sized businesses. From that point of view, the features focus on very high call volume, extensive performance insights, visual call journeys, auto dialer, call blast, and overall contact list management. 

14. LiveAgent

The best part about LiveAgent is its 30-day program evaluation window. Plus, it’s billed annually at around $9 per user, so it’s more of a feasible solution for sales first companies.

Why I Picked This Tool

LiveAgent is primarily a support platform, but made the list due to its flexible outbound calling capabilities, long trial period, and low price.

Standout Features

• 30-day free trial
• Call routing
• IVR
• Call recordings
• Unified helpdesk + phone system

Integrations

• Slack
• Shopify
• Pipedrive
• Zoho
• MailChimp

Pros & Cons

Pros:

• Very affordable
• Great for support-heavy teams
• Long evaluation period

Cons:
– Limited sales-first features
– Not made for high-volume outbound

It’s more of an AIO cloud call center software, which is more focused on rendering help, services, and support to existing customers. The outbound aspect is managed through a few tools, which allow sales teams to place outbound calls, call routing management, interactive voice management etc. 

Frequently Asked Questions

What are the best sales dialer software options for small businesses?

Small businesses don’t have a huge budget. So, their options are limited from that point of view.

If you’re a small business owner or a manager, then you’re already focusing on a high-yield sales dialer software or some type of auto dialer software (*or it could be a combination of different power dialer tools). The idea is to spend less on the program’s monthly cost, have all of your sales team onboarded to make the calls, and get maximum results without wasting any resources.

We’d recommend Trellus.ai. 

Why so?

It’s a robust program with an AIO solution offering for companies focused on sales-first strategies. Especially if you are heading a small business, you could easily sign up for the low-tier pricing plan to get started. Our focus has always been to offer maximum features without slapping extra or hidden fees on different packages.

If Trellus isn’t what you’re looking for, in terms of features, then we’d recommend looking for any reliable sales dialer software online that offers price plans within your monthly budget.

Which sales dialer software offers the most affordable pricing plans?

Aside from Trellus.ai, we would recommend simple solutions such as CallHippo, CloudTalk or Dialpad. Look for their low tier packages. Of course, the value offering in terms of features will vary from one platform to another, but you could always start with a free evaluation plan at no cost and then transition to the basic plan after things work out.

How to integrate a sales dialer software with a CRM system?

Overall, we’d say that integration is pretty much a straightforward process. Most of the time, you don’t have to navigate through complex menus or plugins to do so.

For example, some of the programs discussed in this post come as a Google Chrome extension, or a sign-up only software that works after its integration with your primary CRM environment. 

Aside from that, since this sales calling software supports a huge list of constantly updated CRMs, such as Apollo. HubSpot, Salesloft, Orum, Outreach, etc, the integration is offered within the native CRM’s interface.

Can you recommend a sales dialer software with built in call recording features?

Of course we can!

But do keep in mind that you need to assess your sales business requirements beforehand. Sometimes, a software, despite its features, may not suit your business or drive the same results on par with your expectations because of your unique use-cases, workflows, and stuff like that.

You can try Nooks, Orum, Kixie and such other tools to access their call recordings and post call summaries. 

The best course of action would be to sign up for a free trial account. After that, test the sales calling software with a minimum number of sales reps - i.e. whatever the individual count they allow in the trial plan. See if the pricing and features match your budget, should you switch over to a paid version.

If you’re still confused, ask them for a live demo and forward your questions to the concerned platform’s sales team. Once you’re satisfied, you can easily move on to a paid plan and onboard your entire sales department accordingly.

What sales dialer software tools have the highest call connection rates?

To be honest, no one can answer this question accurately for you.

Connection rates are not a feature depended thing, but sometimes you can attribute it to the number/ volume of outgoing calls. 

To ensure that you have a higher connection rate, you can use an embedded parallel dialer over a single line dialing solution. What it does is that the feature enables you to call multiple contacts simultaneously - and that too, in real time, so that you have a higher chance of getting connected.

Whoever, on the other side, picks up the call first, is connected to your sales rep. This is how parallel dialers work in essence. But they are expensive as compared to traditional auto dialer software, or a power dialer software. 

Trellus’s architecture is basically designed to maximize connect rate because we recently introduced a feature that detects the customer acquisition factor on the basis of the type of numbers that usually work for your business’s sales team. 

That being said, feel free to review different programs before signing up for a solution right away.

What is the main difference between a predictive dialer and a power dialer software product?

A predictive dialer aggressively dials contacts based on the available free time of a sales rep. This happens when a real person/ lead answers the call. Predictive dialers also have an algo that causes the program to pause a little and then dial the next number with a higher connect rate probability. 

Meanwhile, a power dialer (AKA auto dialer) is a back to back dialing solution that automatically calls the next contact on your list as soon as an ongoing call is ended/disconnected. The pacing of these calls can be adjusted by your SDRs. But the main idea behind a power dialer is to reduce time wastage, which normally occurs between intervals when reps aren’t engaged during calls.