| Name | Modified | Size | Downloads / Week |
|---|---|---|---|
| Parent folder | |||
| SHA256SUMS.txt | 2026-11-01 | 187 Bytes | |
| README.md | 2026-11-01 | 2.6 kB | |
| mobidevtools-4.2.1.zip | 2026-11-01 | 243.3 kB | |
| mobidevtools-4.2.1-source.zip | 2026-11-01 | 257.0 kB | |
| Totals: 4 Items | 503.0 kB | 0 | |
MobiDevTools 4.2.1
Developer tools for Firefox on Android and desktop: console, elements, network, sources, Lighthouse-style audits (Pharos), React/Preact, Vue, Angular and Redux/Zustand/NgRx inspectors. Free, open source (MIT), no data collection.
Install from Firefox Add-ons: https://addons.mozilla.org/firefox/addon/mobidevtools/ (signed by Mozilla, updates automatically).
| File | Content |
|---|---|
mobidevtools-4.2.1.zip |
The extension package, the same as submitted to addons.mozilla.org. Load it in Firefox Desktop from about:debugging → Load Temporary Add-on for development. |
mobidevtools-4.2.1-source.zip |
Full source with documentation (README.md, PLUGINS.md, CHANGELOG.md), plugin examples and the automated test suite (test/suite42.js, test/suite421.js). |
SHA256SUMS.txt |
Checksums. |
Documentation: https://mobidevtools.sourceforge.io/
What's new in 4.2.1
A privacy and hardening release, after a full self-review against Mozilla's add-on policies. No new permissions.
- Request bodies (form fields, JSON payloads) are kept only for tabs where you opened MobiDevTools.
- Closing with ✕ stops all capture for that tab; reopening starts it again.
- Cookies only to the page's own site when Sources/Network re-download a resource.
- New option "Remember console history" (on by default); turning it off erases it. Nothing is saved from private windows.
- Console code accepted only as text, only from MobiDevTools and only from a tab where it is open. Page plugins: max 8, unique ids, clean titles.
- Tests: new hardening suite 23/23 (12 fail on 4.2.0), the 74 checks of 4.2 still pass, addons-linter 0/0/0.
What's new in 4.2
Thanks to Halkion for the review that suggested these changes.
- Close MobiDevTools completely. The ✕ removes the panel and the floating button, gives the page its space back and stays closed after a reload. Reopen it from the toolbar button (desktop) or menu › Extensions (Android).
- Outline on the selected element. After you pick an element it keeps a blue outline with tag, id, classes and size, like the Firefox inspector. It follows scrolling and layout changes and goes away with Esc, a new pick or when the node is removed.
- Panel shrinks while picking. During inspection the panel becomes a thin bar with Cancel, so it no longer covers the page.
- Fixed: the panel's shadow no longer stays visible at the bottom of the page when the panel is closed.
- New test suite on real Firefox, desktop and phone layout: 74 checks.
