What is the ROFL file format?
The .rofl file is a League of Legends replay - a proprietary binary recording created by the official Riot Games client. Unlike a video file, a .rofl replay does not store frames; it records the stream of game inputs and state events captured during a match, which the client engine then re-simulates on playback.
.rofl files can be saved from the in-client Match History panel after a match ends. There is no limit on how many times you can watch a locally saved replay. However, because each file encodes game logic tied to a specific patch version, replays become incompatible - and are deleted - with each new patch installation. Since League of Legends is updated roughly every two weeks, .rofl files are cleared from disk regularly.
Every .rofl file begins with the ASCII magic signature RIOT (hex 52 49 4F 54) at byte offset 0. The file header stores match metadata alongside a JSON blob containing per-player end-of-game statistics; the remainder holds the proprietary, encrypted stream of game events the client replays.
League of Legends is one of the most popular MOBA games worldwide and is available under a free-to-play model. Optional in-game purchases do not affect core gameplay - only cosmetics and progression speed.
.rofl files can only be opened with the official Riot Games client; no independent third-party player exists for this format. A comparable replay approach is used by .wotreplay in World of Tanks.
Security & safety
RISK: LOWA ROFL file is data played only by the official League of Legends client, so it is not an executable threat in itself. The realistic risks are practical: a replay only works on the patch it was recorded on, so old files will simply fail to open after an update (not a sign of corruption). Only download .rofl files from your own Match History or trusted sources - and ignore websites or 'ROFL viewer/converter' downloads promising to turn replays into video or to 'unlock' them, as those are the usual vector for bundled adware/PUPs around game-file searches.
Format details
in a nutshellPrograms that open ROFL files
Windows3 apps
League of Legends (Riot client)
Free Double-click the .rofl (or drag it onto the game) - the League client launches and plays the replay. Must be the current patch.
League of Legends - in-client Match History
Free In the client: Profile > Match History, find the game, click Download, then Watch - the supported way to get and play replays.
OBS Studio (to record a video)
Open-source Play the replay in League, capture the game window with OBS and record to MP4 - this is how you actually 'export' a replay to video. 
macOS2 apps
League of Legends (Riot client)
Free Double-click the .rofl to launch League and play the replay (League runs on macOS). Patch must match.
OBS Studio (to record a video)
Open-source Capture the League window while the replay plays to record an MP4 clip on Mac. Technical details
deep spec| File signature (magic bytes) | `RIOT` (hex `52 49 4F 54`) at byte offset 0 |
| Format type | Proprietary binary replay - stores game events and state inputs, not video frames |
| Developer | Riot Games, Inc. |
| MIME type | `application/octet-stream` |
| Header contents | Match metadata and a JSON blob of per-player end-of-game statistics |
| Payload encoding | Proprietary encrypted stream of game events re-simulated by the League of Legends client engine |
| Patch compatibility | Valid only for the patch version it was recorded on; newer patches render the replay unplayable |
| Lifecycle | Automatically deleted from disk when a new game patch is installed |
| Playback controls | Supports timeline scrubbing, playback speed control, and free-camera mode during in-client replay |
| Supported platforms | Windows and macOS (official Riot Games client) |
| Playback application | Official League of Legends client only; no independent third-party player exists |
| Access method | Saved via the in-client Match History panel after a match ends |
| View limit | No restriction on how many times a locally saved `.rofl` file may be replayed |
| File naming | Typically named `{region}-{matchId}.rofl`, e.g., `NA1-1234567890.rofl` |
| Related format | `.wotreplay` - World of Tanks uses a comparable patch-tied binary game-event replay approach |
| Released | 2016 (in-client replay system, League of Legends patch 7.x era) |
| Specification | support-leagueoflegends.riotgames.com |
ROFL conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about ROFL files.
