Free Auto Dialer Software: The Complete 2026 Guide

A free auto dialer takes the busywork out of outbound calling, so your agents spend their time talking to people instead of punching in numbers. And the options that are actually free, not just free to start, are the open source ones: you download them, host them yourself, and never pay a per-seat fee. Below, I’ll walk through how they work and which open source projects on GitHub are worth a look.

What is auto dialer software?

An auto dialer dials numbers from your contact list on its own and connects the answered calls to a live agent or a recorded message. Nobody sits there hitting digits. The software works the queue, skips busy signals and voicemails, and logs every result, which for outbound sales, collections, surveys, or appointment reminders adds up to a lot more conversations per hour.

Here’s the thing though: not every dialer behaves the same way. What separates them is how aggressively they place calls, and that one choice decides whether your agents sit idle or whether you start dropping calls on the people you reach.

Auto dialer

The umbrella term for any software that dials numbers from a list without manual input.

Preview dialer

Shows the agent the contact record first, then dials when the agent is ready. Best for complex, high-value calls.

Progressive dialer

Places one call for each free agent, so nobody dials ahead of available staff. Low abandon rate, steady pace.

Predictive dialer

Uses live statistics on answer rates and call length to dial several numbers ahead of free agents, pruning idle time. Highest throughput, needs careful pacing to stay compliant.

What makes an auto dialer free and open source

The auto dialers that stay free are the open source ones. You grab the source code, install it on a server you own, and run as many campaigns and agents as the hardware can handle, with no license to renew. Your only costs are the server and your SIP minutes. And since the code is out in the open, you can read it, change it, and keep your call data on your own machine rather than someone else’s cloud.

Most of these projects ship under copyleft licenses like GPL or AGPL, which is what keeps them free to use and study. Nearly all of them sit on top of one of two open source telephony engines, Asterisk or FreeSWITCH, and that engine is worth paying attention to because it shapes how the dialer places and paces every call.

How an open source auto dialer works

It looks like a lot of moving parts, but the flow is simple once you see it laid out. The dialer pulls numbers from your contact list, hands them to a telephony engine that actually places the calls, and pushes the answered ones through to agents in their browser. Everything that happens gets written back to a database you own.

Because agents connect through WebRTC, they only need a browser and a headset. No desk phones, no client software to install. That single design choice is what makes a free, self-hosted dialer practical for remote teams.

Best free and open source auto dialer software

Here are the open source dialers worth knowing about, all free to download and run on your own server. The star counts in brackets come from each project’s public GitHub repo, so you can go read the code yourself before you commit to anything.

ICTDialer (FreeSWITCH-based)

ICTDialer runs on the FreeSWITCH engine and the ICTCore framework, and it’s built for multiple users and tenants from the start. You get the usual preview, progressive, and predictive campaigns, but it also reaches past plain calling into voice broadcasting, fax, and SMS from the same place. Agents just need a browser and WebRTC, and because it’s white-label, service providers can put their own brand on it and resell. It’s GPL-3.0 and sits at around 100 stars on GitHub.

ViciDial (Asterisk-based)

ViciDial has been around for years and is probably the most deployed open source dialer out there, with the project citing more than 4,000 active installations. It runs on Asterisk and gives you predictive dialing plus blended inbound and outbound on a single agent screen, all through a PHP and Perl web interface. It’s proven and packed with features. The flip side is an interface that feels dated, and getting it set up goes smoother if you already know your way around Asterisk. It’s released under the AGPL.

GOautodial (Asterisk-based)

GOautodial takes that same ViciDial and Asterisk core and puts a much more modern face on it, with a cleaner web UI, REST APIs, and a plugin system. It does predictive, preview, and manual dialing, then adds inbound IVR, ACD, and non-voice channels, so it pulls toward a full omni-channel contact center rather than just a dialer. It’s AGPL and runs around 130 stars on GitHub. Reach for this one if you like the ViciDial engine but want nicer tooling and an API you can actually build against.

Any of the three will run for as many agents as your server can take, free. Which one fits comes down to a few questions: do you prefer Asterisk or FreeSWITCH under the hood, do you need fax and SMS next to voice, and do you care more about a slick interface or a long, proven track record? If you want to compare more options, we keep a wider roundup of open source auto dialer software solutions.

How to choose: a quick checklist

• Decide whether you need preview, progressive, or predictive pacing for your call type
• Check the real cost at your team size, not just the headline “free” price
• Confirm where your call data and recordings are stored
• Make sure the dialer respects DNC lists and local calling-time rules
• Look for browser-based agents so onboarding stays simple
• Test answer detection, because poor voicemail filtering wastes agent time