Reduces wasted ad spend by providing a more accurate way to measure campaign effectiveness than basic attribution.
What is Google Meridian?
Google Meridian is an open-source media mix modeling (MMM) tool built by Google, and it is free for anyone to use.
You download the framework, connect your own marketing and sales data, and run the models on infrastructure you already pay for.
Google positions it as the answer to 3 questions: what each channel contributed historically, how impact scales with spend, and where the next dollar should go.
Google opened Meridian to everyone back in January 2025 for better marketing budget allocation.
Meridian is a $0 modeling framework for businesses that have outgrown last-click answers.
Is Google Meridian actually free to use?
Yes, the tool is free: the codebase is fully open for you to inspect and modify, and there is no license payment anywhere in the setup.
In the new Ads Decoded episode, Patrick Gilbert and Nechama Teigman from AdVenture Media give an unvarnished walkthrough of implementing Meridian.
Google’s own measurement lead, John Chen, frames the shift that makes this reachable: AI coding tools erase the technical barriers that used to make MMM a specialist-only job.
The pairing matters for credibility: Ads Product Liaison Ginny Marvin sits down with John Chen, Google’s Senior Director of Product Management for Ads Measurement, so the stack talk comes from the people who build it.
The claim to read carefully is what “free” covers: the license costs $0, while data variance, not budget size, decides whether the output is worth anything.
The license is $0 and the real cost is now your data prep.
Is Google Meridian good enough to replace paid attribution software?
Meridian is not built to replace attribution, and Google’s measurement leads describe a stack across attribution, incrementality tests, and MMM running together on purpose.
Attribution tracks live clicks in short windows, while MMM models the longer journey, which is why Google built Qualified Future Conversions to capture sales that close after the standard window ends.
Google’s own guidance describes MMMs as a holistic read on all media channels, sales, and external factors like seasonality and pricing, which is a different job than counting clicks.
Paid platforms still win on speed for daily campaign decisions, and a quarterly MMM run will never tell you which ad to pause tomorrow morning.
The practical split: attribution and incrementality tests answer what happened this week, while MMM answers where next quarter’s budget should go. The stack is how you run both time scales without letting one lie for the other.
Meridian replaces the paid MMM invoice, not your attribution tool.
Three dashboards sit open on the counter before the first job of the day, and each one names a different best channel. The ad platform credits the click, the CRM credits the coupon code, and the bank account credits none of them. Someone still has to decide where next month’s budget goes.
That disagreement is the exact problem a measurement stack solves, and it used to be a problem money solved: pay a specialist, get an answer. With the modeling layer priced at $0, the remaining cost is who runs it and how clean your data is.
The trade worth staring at: a free model you own, or a paid dashboard you rent. One of them tells you what your spend actually did.
Is Google Meridian right for your business?
This is for owners spending across multiple channels where getting the allocation wrong costs real money, not for anyone running a single traffic source.
It’s less useful with a short, linear purchase journey, where plain attribution already sees most of the story.
A single-channel shop already knows what worked, and a short purchase cycle closes inside most attribution windows anyway, so the model would only confirm what the dashboard shows.
Measurement is one signal among many that move a small business, so it pays to keep watching the wider field: you can start by tracking your growth signals.
Meridian is for founders who have to prove their ad spend drives growth instead of clicks.
Should you use Google Meridian instead of paying for a measurement consultant?
Run Meridian yourself if you have someone who can drive AI coding tools through the setup, because that is the documented path Google’s guests used to get it live.
A consultant sells you a finished answer, while the open-source framework leaves you a repeatable process you own and rerun every quarter without another invoice.
The trade-off is your team’s setup time against the consultant’s retainer, and with the license at $0, time is the only currency left in the decision.
Budget it like a project, not a purchase: the episodes close on how to plan your next strategic test, and the framework expects your historical channel data before it says anything worth acting on.
Own the process when you can, and buy the answer when you can’t.
Source: Google AI Blog
