01Location
- <User Data>/<Profile>/Favicons
02Questions it answers
- Which page URLs had icons stored, including pages that may no longer appear in History?
- When was a site's icon last fetched on a visit?
- What did the site icon look like (PNG data)?
03Format and versions
| Format | SQLite 3 database, schema version 9 (versions 7 and earlier are deprecated and cleared at startup). Times are int64 µs since 1601-01-01 UTC. |
|---|---|
| Applies to | Chromium main branch as read on 2026-10-14 (version 9 dated 2025-01-28; version 8 dated 2015-03-31). |
04Key fields
| Field | What it tells you |
|---|---|
| icon_mapping (id, page_url, icon_id, page_url_type) | Maps a page URL to one or more favicons. |
| favicons (id, url, icon_type) | Icon URL and its type from the link rel attribute; type 1 is the default favicon. |
| favicon_bitmaps (id, icon_id, last_updated, image_data, width, height, last_requested) | PNG-encoded bitmap per size, linked to favicons.id. |
05Timestamps
| Field | Encoding | Note |
|---|---|---|
| favicon_bitmaps.last_updated | int64 µs since 1601-01-01 UTC | When the bitmap was inserted; 0 means explicitly expired. Used for ON_VISIT icons; always 0 for ON_DEMAND icons. |
| favicon_bitmaps.last_requested | int64 µs since 1601-01-01 UTC | Non-zero only for ON_DEMAND bitmaps; used to clear old on-demand icons. |
Decode raw values with the Timestamp decoder and convert local wall-clock times with the Local time to UTC.
06Examination workflow
- Join icon_mapping → favicons → favicon_bitmaps on icon_id/id.
- Compare page_url values with urls.url in History to find pages present only here.
- Interpret last_updated only for rows where last_requested is 0 (ON_VISIT).
- Export image_data as PNG for visual identification of the site.
07Interpretation pitfalls
- On-demand bitmaps have no corresponding visit in History, so an icon row alone does not prove a visit.
- The database is a cache; the source treats data loss as acceptable and clears deprecated versions.
- Many pages on one site share the same icon, so the icon does not identify which page was viewed.
09Sources
- Chromium source — components/favicon/core/favicon_database.cc The Chromium Authors (GitHub mirror) · checked 2026-10-14
- Chromium source — history_constants.cc (kFaviconsFilename) The Chromium Authors (GitHub mirror) · checked 2026-10-14
- Chromium source — sql/statement.cc (BindTime / ColumnTime) The Chromium Authors (GitHub mirror) · checked 2026-10-14