Methodology: how FirmwareIndex collects Samsung firmware data
Every number on FirmwareIndex comes from one source: Samsung's public firmware update service. This page explains what we read from it, how we turn it into dates, regions and bootloader bits, and what the data cannot tell you. Pages across the site link to the section that backs each statement.
Source · Dates · Regions · “Pulled” · Bootloader bit · Update type · Android version · Security patch level · Update frequency · Limits · Corrections
Source: Samsung's firmware update service
Samsung's update servers (FUS) answer firmware queries for a model code and a region code (CSC). One of their endpoints returns the build history of that pair: every firmware version Samsung lists for it, with an open date, the Android version, whether the file is still available and whether the build is a beta. We query this history for every model and region code we track and store each build once per model and region. We do not copy data from other firmware websites, forums or Samsung's press releases.
The service is not documented by Samsung. Our client follows the open-source protocol implementation of samloader-rs and checks itself before every crawl. If Samsung changes the protocol, collection stops and pages keep the last known state.
Dates: “released” and “first appeared”
For each build and region, Samsung's history lists an open date. We take it as the date the build became available for that region on Samsung's servers. “Released” or “first released” on a model or build page is the earliest of these dates across all regions. Per-region columns show the date for that code.
- The open date is not the day your phone shows the update. Samsung rolls updates out over the air in stages, sometimes over several weeks, after the build is open on its servers.
- It is also not the date of Samsung's announcement or the security patch month in the release notes.
- Samsung reports the time in Korean time (KST, UTC+9). We convert it and show dates in UTC. Until November 7, 2026 we read these times as UTC, which put builds up to nine hours too late. All stored dates were corrected on that day.
- If Samsung lists the same build twice (it does so for different binary types), we keep the earlier date.
Regions (CSC codes)
A region code (CSC) identifies a country, a carrier or a group of countries, for example EUX for unbranded European devices or XAA for unlocked US devices. A build “has reached N regions” when Samsung's history lists it for N of the codes we track for that model. “Still waiting” and “not yet released in” list codes that are active for the model but still show an older build as their latest.
Which codes exist for which model we determine ourselves by asking Samsung's service for each combination. A code that returns no history is not counted. We track 24,862 model and region pairs (November 2026). A code missing from our list does not prove that Samsung does not ship the model there.
“Pulled”: file no longer served
A build marked pulled is still listed in Samsung's history, but Samsung reports that the file is no longer available for download. In almost all cases this is ordinary housekeeping: Samsung removes older builds once newer ones are out. Nearly all “pulled” entries in our database are more than a year old.
“Pulled” therefore does not mean that Samsung recalled or withdrew a faulty update. A build that disappears from the history entirely is not yet detected as a separate status.
Bootloader (binary) bit
The bootloader bit is read from the build number itself: it is the fifth-last character of the PDA version (0–9, then A = 10, B = 11 and so on). A device on bit N only accepts firmware with bit N or higher. The build number decoder shows every position. The downgrade guide explains the consequences.
Update type: security or feature
The sixth-last character of the build number is S or U. We label S as a security update and U as a feature update. This is Samsung's own build classification, not a statement about the content: a security update can contain bug fixes, and a feature update also contains the current security fixes.
Android and One UI version
The Android version comes from the operating-system name Samsung returns for each build. The One UI version is derived from it. An “Android upgrade” is a build whose Android version is higher than that of the previous stable build of the model.
Security patch level: not shown
Samsung's update service does not return the security patch level. We therefore do not state a patch month for any build. Model, region and build pages link to Samsung's official release notes on doc.samsungmobile.com, which list the patch level of each update.
Update frequency
Every model and region pair with a build from the last 180 days is checked every 24 hours. Older pairs, which rarely receive updates, are checked weekly. Pages are rebuilt every morning (Central European Time). Because dates come from Samsung's history, a build we find late still gets its original date.
Limits
- We only cover models and region codes we have found on Samsung's service. New models are added as we discover them.
- Samsung's history may not reach back to a model's launch in every region. Build counts mean “builds Samsung lists”.
- Beta builds are listed separately and are not counted as releases.
- Update commitments on the update policy page come from published statements by Samsung and the press. Each row names its source.
Corrections
- November 7, 2026: open dates converted from Korean time to UTC (see Dates).
Found an error? Write to contact@firmwareindex.com.