Footprint

Footprint is a performance profiler that tells a WordPress administrator which plugins and which theme have the highest impact on the performance of a given page, and what to do about it. A lighter site is also a more sober site, both for your visitors and for the planet.

Unlike profilers built for developers (Query Monitor, Code Profiler), Footprint is decision-oriented. In thirty seconds you should know:

• which plugin or theme slows the page the most,
• which one ships the heaviest JS/CSS,
• which one issues the most SQL queries,
• which one consumes the most memory,
• which one calls external services,
• whether the active theme has a meaningful footprint of its own,
• what to optimise first.

When you re-scan the same URL, the report shows what changed since the previous scan: score, server time, memory, SQL, external calls, and the components whose impact moved most.

How it works

Footprint runs a differential scan: it loads the target URL once with everything active (baseline) and once per plugin with that plugin disabled, for the duration of a single internal HTTP request only. The difference between the two runs gives a real measurement of that plugin’s footprint, not an estimation.

A small must-use plugin loader performs the per-request swap. You install it in one click the first time you scan (it lives in wp-content/mu-plugins/, outside this plugin’s folder, and is removed on uninstall). Nothing is changed in your database.

The whole report you see on screen is computed locally on your server: the per-component impact on time, memory, SQL and assets, the ranking of the heaviest components, and the optimization advice. The plugin is fully functional on its own. The only thing that needs the Footprint Pulse service is the A-E Footprint Score, which compares your result against the anonymized measurements of thousands of other sites and cannot be computed locally.

Honesty about limits

Footprint provides estimated measurements where exact attribution is impossible. WordPress loads the core, plugins and theme inside the same PHP process, which makes perfect per-plugin memory attribution unreliable. The differential scan greatly improves the signal but it is still subject to:

• run-to-run variance (typically 5-15%),
• dependency cascades (disabling a parent plugin can disable extensions of it),
• page caches (a cached page bypasses PHP and yields no useful measurement),
• opcode and object cache warm-up effects.

The report flags any of these conditions when detected.

Privacy

Footprint includes a community ranking called Footprint Pulse. Sharing is on by default and can be turned off any time in Settings. The plugin’s local report, per-component impact and recommendations work exactly the same either way. The only thing sharing adds is the community A-E Footprint Score described above.

When sharing is enabled, after each scan the plugin sends to https://www.wpfootprint.com:

• the slug and version of each measured plugin and the active theme,
• time, memory and SQL counts attributed to each component (the same numbers shown on screen),
• the number of scripts, styles and external HTTP calls each component added,
• WordPress, PHP and MySQL versions,
• an anonymous site identifier generated locally on your server.

Read the full description on the official page →