whatismmm

LightweightMMM

Deprecated MMM library (Python)

Open source, license $0, and no longer the point: it is deprecated.

LightweightMMM was Google's first open-source MMM library, built on JAX and NumPyro. It gave many teams their first Bayesian media model and seeded much of the current open-source ecosystem's vocabulary.

Google has since replaced it with Meridian, and the LightweightMMM repository points users there. The library is not under active development.

Should anyone start a new build on it in 2026? No. Existing models keep running, but new work belongs on Meridian, PyMC-Marketing, or Robyn, all actively maintained. This page exists because the SERP still sends people here; consider it a signpost.

At a glance

Status
Deprecated. The repository directs new users to Meridian.
Migration
No automated migration; Meridian is a new model specification, not a version bump.
If you run it today
Plan the port before the person who built your model leaves. That is the actual deadline.

Who it is right for

Verdict: A signpost, not a tool. Start on Meridian or PyMC-Marketing instead.

Source ledger

Every numeric claim on this page resolves to one of these primary sources.

  1. [1]LightweightMMM repository (GitHub)https://github.com/google/lightweight_mmmretrieved 2026-08-02
  2. [2]Google Meridian documentationhttps://developers.google.com/meridianretrieved 2026-08-02