# F5 BIG-IP license explainer > Paste your /config/bigip.license, full file or a fragment, and get a plain-language reading: management flavor, licensing dates with the K7727 upgrade verdict, Registration Key and platform, active and optional modules, constraints, and feature tokens. Runs entirely in your browser. - Tool: https://ronutz.com/en/tools/f5-bigip-license-explainer - Family: Networking --- # F5 BIG-IP license explainer Paste the contents of `/config/bigip.license`, the full file or any fragment, and get a plain-language reading of what the license actually says. The parser runs entirely in your browser: nothing is uploaded, and key or signature values are never displayed, only their presence and length. ## What it reads The explainer decodes the whole observable structure of the file. It identifies the management flavor: a `BIG-IQ Product License File` header together with `license_manager_key` or `pool_license_information` fields marks a license managed by BIG-IQ License Manager, while a `BIG-IP System License Key File` header marks one licensed directly on the system. It reads the identity block (`Auth vers`, `Usage`, `Vendor`), the licensing dates (`Licensed date` and `Service check date`, both in the file's compact `yyyymmdd` form), the `Registration Key` (checked against the published 5-5-5-5-7 shape from F5 K7752 and K3782), the `Licensed version`, and the `Platform ID` with a conservative decode (Z100-family means BIG-IP Virtual Edition, per F5 K02011230; unmapped IDs point you to F5 K9476). Modules are read from their real grammar: each `active module` line is pipe-separated into the module name, that module's own 7-7 key, and its feature list, and a file can carry several such lines with distinct keys. `optional module` lines list features that are licensable but dormant until licensed. Repeatable `Exclusive_version` lines (the permitted software range, per F5 K42091606), `Deny_version` lines, and `Exclusive_Platform` lines are collected into constraint lists, and every remaining feature or limit token (`perf_VE_throughput_Mbps`, `mod_ltm`, `asm_apps`, and the rest) is shown with its value normalized: the file uses both `enabled` and `enable`, and both `UNLIMITED` and `unlimited`. ## The K7727 verdict The `Service check date` is judged against F5's License Check Date table (K7727) using the same vendored table the F5 service check date tool uses, so both tools always agree: you see the newest version this license can boot and the nearest branch that would require a reactivation first. ## Using it Paste and read; the Example button loads a masked, structure-faithful sample. Treat the file as sensitive: it carries your registration key, per-module keys, and the Dossier and Authorization signatures. This tool never displays those values, and because field meanings are vendor documentation rather than a fixed standard, confirm licensing decisions against F5's own documentation or support. ## Standards and references - [F5 K000160443 - Understanding the output of tmsh show sys license on BIG-IP](https://my.f5.com/manage/s/article/K000160443) - field-by-field meaning of the license fields (Licensed On vs Service Check Date vs License End Date, Registration key, Platform ID, Licensed Version) and the /config/bigip.license file location - [F5 K7727 - License activation may be required before a software upgrade for BIG-IP](https://my.f5.com/manage/s/article/K7727) - the Service Check Date definition and the per-version License Check Date table used for the upgrade-eligibility verdict (via the sibling f5-service-check-date engine) - [F5 K3782 - Finding the serial number or registration key of your BIG-IP system](https://my.f5.com/manage/s/article/K3782) - the registration key sample shape (5-5-5-5-7) and the license field set as shown by tmsh - [F5 K7752 - Licensing the BIG-IP system](https://my.f5.com/manage/s/article/K7752) - the 27-character base registration key and the add-on (per-module) registration key model - [F5 K42091606 - Determine your BIG-IP VE SKU and permitted software version range](https://my.f5.com/manage/s/article/K42091606) - Exclusive_version fields in bigip.license define the permitted software range for VE Version Plus licenses - [F5 K15643 - BIG-IP VE Version Plus license offerings](https://my.f5.com/manage/s/article/K15643) - Version Plus semantics: the permitted-range ceiling embedded in VE SKUs, which the Exclusive_version ceiling corresponds to - [F5 K02011230 - Platform ID change for BIG-IP VE systems](https://my.f5.com/manage/s/article/K02011230) - Z100-family platform IDs belong to BIG-IP Virtual Edition ## Related reading - [Anatomy of a BIG-IP License File](https://ronutz.com/en/learn/bigip-license-file-anatomy.md): The /config/bigip.license file is human-readable, and learning to read it answers real operational questions: which modules are actually licensed, what the throughput and session limits are, whether an upgrade will load, and whether BIG-IQ is managing the license. Here is the file, section by section, from two real lab licenses. - [BIG-IP, TMOS, and F5OS: A Version Timeline You Can Slide Through](https://ronutz.com/en/learn/bigip-tmos-version-timeline.md): BIG-IP the platform and TMOS the software were the same thing until 2004, when version 9.0 split them and moved the box from BSD to a Linux host with the TMM microkernel. This interactive timeline slides from the 1997 BIG-IP Controller to BIG-IP 21.0, showing the software version and the operating system underneath it at each step, including why the numbers jump straight from 17 to 21.