.replay file
Short answer: Fortnite opens it, nothing else does.
A .replay is not a video file, and no codec, plugin or converter changes that. Below: how to play it back, and three honest ways to show the match to someone else.
A video is a sequence of pictures. A replay is the opposite: it stores what happened — where every player was, every elimination with location and weapon tag, damage, placement — and the pictures exist only while Fortnite plays the match out again on your machine. That is also why the file is small: Epic puts a full match at about 10 MB.
The trade-off is the version rule. Because the game has to re-simulate the match, Epic states a replay only plays back in the version of Fortnite it was recorded in, and that after an update old replays are no longer valid unless they were saved — saving being to select it in the replay browser and rename it.
Inside the game, not from the file.
Epic documents replays as living under the Career tab in the Fortnite lobby, where the replay browser lists your matches.
Anything from before the last update is likely gone. A match that matters to you: rename it here and it survives the patch.
The match runs again, with a free camera. This is also the only place a video of it can come from.
The file behind that entry lives in one folder on Windows — you only need it to do something outside the game with it:
%LOCALAPPDATA%\FortniteGame\Saved\Demos
More on that folder, the UnsavedReplay naming and the recording switch: where Fortnite saves replay files.
Ranked by how likely they are to work at the other end.
Works for anybody, on any device, forever: play the replay back and capture your screen. Epic's own note is the reason not to put it off — stills and video have to be captured before a chapter or season update, because the replay stops being playable then.
On PC the replay is an ordinary file, so you can copy it — but it stays bound to the Fortnite version that recorded it and stops being useful at the next patch. On PlayStation and Xbox the option does not exist: Epic documents no way of reaching the file on a console.
Upload the replay once, send the link to the report. It opens in a browser — no account, no install, any platform — and it does not stop working when Fortnite updates.
Fortiq reads the same file the game reads. Out of it comes the match record: where everyone was, every fight and elimination with its location and weapon tag, damage and placement — and the one thing that cost you the match. You can then ask the coach about it. Three full reports a week, free, no download.
What is not in it: your crosshair, your inputs, your edit speed, your screen. None of that is in the file, so nothing reports on it. Where the data runs out, the report says so instead of filling the gap.
Fortnite itself. Epic documents replays under the Career tab in the lobby; they play back inside the game. No media player, codec pack or converter opens one.
Not by converting the file — there are no pictures in it. Play the replay and capture your screen. Epic notes this has to happen before a chapter or season update, because the replay stops being playable then.
Epic states that you can only play a replay back in the version of Fortnite it was recorded in, and that after a new update old replays are no longer valid unless they were saved. Saving one means selecting it in the replay browser and renaming it.
On PC it is an ordinary file, but it still only plays in the version that recorded it. On PlayStation and Xbox, Epic documents no way of reaching the file. A report link travels better: any browser, any platform.
Yes, with no sign-in. The example report is the same kind of page a link to your own match produces.
Three full reports a week, free. The link opens without an account.