Free marketing mix modeling software: the open-source options, what they cost to run, and what else is free
The main free marketing mix modeling software is open-source code: Meta's Robyn, Google's Meridian and PyMC Labs' PyMC-Marketing. All three are free but ship no interface, connectors or support, so the cost moves to the people who run them, and vendor trials are rare.
Free means code that costs nothing to download and a good deal to operate, or a commercial product at no charge for a period, which few vendors offer.
The three open-source libraries
- Robyn, from Meta: ridge regression with automated search over adstock and saturation, returning point estimates. Suits R teams wanting a fast start.
- Meridian, from Google: a Bayesian Python model that returns a distribution for each channel's effect. Suits Python teams modeling many regions.
- PyMC-Marketing, from PyMC Labs: a Bayesian Python library with wide control over model structure and priors.
All three can take experiment results as calibration.
What running an open-source library involves
The code is the one free part. The rest recurs every cycle.
- Data pipeline: spend and outcomes pulled on a schedule, fixed when an export changes.
- Modeling work: variables, delayed-effect and saturation settings, priors, validation.
- Refreshes: refit as new weeks arrive, and check for drift.
- Interpretation: explain the output and turn it into a budget plan.
- Calibration: experiments such as geo tests, designed and run by the team.
How rare vendor trials are
- Trials: commercial vendors seldom offer one. Some list a free plan, Improvado and Triple Whale among them; check current terms. Captured 14 September 2026.
- Pricing: published more often, though still not by most vendors.
- If a trial exists: check history limits, connectors, experiments, and what happens to the data afterwards.
What to check before starting with anything free
- History: two or more years of weekly data, with varied spend per channel.
- People: modeling and engineering skills, and time beyond the first model.
- Checking: at least one experiment to calibrate the model.
- After the first result: a budget for refreshes and maintenance.
What to know about Cassandra here
- Not open-source code. Start Cassandra for free with your website and data. Paid plans scale with yearly ad spend.
- History still matters. A channel needs enough spend history and variation, paid or free.
- Geo experiments need regional structure, and tests take a few weeks.
- Want code you control? The three libraries above are good options.
How to choose
- A modeler with time, wanting control: an open-source library.
- Unsure your data supports a model: a library or free tool, before paying.
- Results on a schedule, nobody to maintain a model: a paid platform. Compare its price with the people a library needs.
Cassandra is an AI marketing brain for growth teams, not a library: a Bayesian marketing mix model checked by live geo experiments, doing the work within the rules the team sets. Start for free with your website and data.
Moving from free to paid, or the other way
- Library to platform: the cleaned history is the main asset. Run both on the same period first.
- Platform to library: ask for exports of data, outputs and settings.
- Both ways: keep the experiment record. Test results stay valid evidence.
Questions
Is there free marketing mix modeling software?
Yes, as code. Meta's Robyn, Google's Meridian and PyMC-Marketing are open source and free to download. None ships an interface, connectors or support.
Do marketing mix modeling vendors offer free trials?
Rarely. Among the vendors we looked at, Forvio, Hyros, Improvado, Rockerbox and Sellforte mention a trial or free tier on the pages we could reach, as of 14 September 2026.
Why do so few MMM vendors offer a trial?
Because a meaningful result needs real historical data ingested and cleaned first, which is setup work done before anyone knows whether the result will be useful.
What does an open-source MMM library cost to run?
The code is free. A data pipeline, modeling work, refreshes, interpretation and calibration experiments recur every cycle.
Which free MMM library should I use?
Robyn suits R teams wanting fast automated model search. Meridian and PyMC-Marketing suit teams that need uncertainty in the results, with Meridian oriented to geo-level data and PyMC-Marketing offering the most control.