01Location
- <Firefox profile>/formhistory.sqlite
02Questions it answers
- What did the user type into forms or the search bar?
- When was a value first entered and when was it last used?
- How many times was the same value submitted?
03Format and versions
| Format | SQLite 3 database. firstUsed, lastUsed and timeDeleted are microseconds since 1970-01-01 UTC (JavaScript Date.now() × 1000). |
|---|---|
| Applies to | Firefox main branch as read on 2026-10-14. Default retention preference browser.formfill.expire_days = 180. |
04Key fields
| Field | What it tells you |
|---|---|
| moz_formhistory (id, fieldname, value, timesUsed, firstUsed, lastUsed, guid) | One row per field name and value pair. |
| moz_deleted_formhistory (id, timeDeleted, guid) | Deletion records; the source enables this table by default only on Android. |
| moz_sources (id, source) and moz_history_to_sources (history_id, source_id) | Optional association of entries with a source string. |
05Timestamps
| Field | Encoding | Note |
|---|---|---|
| firstUsed, lastUsed | int64 µs since 1970-01-01 UTC | All entries written in one batch share the same 'now' value. |
| timeDeleted | int64 µs since 1970-01-01 UTC | Present only where the deleted table is used. |
Decode raw values with the Timestamp decoder and convert local wall-clock times with the Local time to UTC.
06Examination workflow
- Copy formhistory.sqlite with any -wal file.
- Convert firstUsed and lastUsed by dividing by 1,000,000 and sort by lastUsed.
- Group by fieldname to separate search-bar input from website form fields.
- Correlate lastUsed with places.sqlite visits to identify the site.
07Interpretation pitfalls
- Entries older than the expire_days preference (default 180 days) are removed.
- No URL is stored with the value; site attribution requires correlation.
- Form history can be disabled (browser.formfill.enable); an empty table may reflect configuration.
09Sources
- Firefox source — toolkit/components/satchel/FormHistory.sys.mjs Mozilla (GitHub mirror) · checked 2026-10-14
- Firefox source — modules/libpref/init/all.js (browser.formfill.* defaults) Mozilla (GitHub mirror) · checked 2026-10-14
- Profiles — Where Firefox stores your bookmarks, passwords and other user data Mozilla Support · checked 2026-10-14