Editing Replay

Replays were introduced with ''Brawl''. When a match concludes, players can press the {{button|Wii|Z}} button, or the {{button|Wii|B}} button on a lone [[Wii Remote]], to save a replay onto either the Wii or an [[SD card]]. Replays can only be saved if the match lasted less than 3 minutes, [[Sudden Death]] included. The reason for this limit is unknown, as a number of hacks can remove this limit; even with such hacks, however, replays over 10 minutes do not function properly, as replays stop saving inputs beyond the 10 minute mark.

Replays returned for both versions of ''Smash 4'', with players instead pressing {{button|3DS|Y}} on the third page of the results screen. The time limit for replays was expanded to about ten minutes, allowing for greater freedom in what replays can be saved. The 3DS version has a hard cap for how many replays can be saved of only 64. The Wii U version has a cap of 4,096 due to the naming scheme of the replays; replays use a 3 digit {{iw|wikipedia|hexadecimal}} index and are named <code>rd000.bin</code> to <code>rdfff.bin</code>. Replays can no longer be saved if a match is aborted (i.e., on the No Contest screen). On the Wii U version, the option to upload replays to [[YouTube]] and [[Miiverse]] directly from the console was available. After connecting a YouTube account to the Wii U, the option to automatically upload will appear, and an unlimited amount of replays can be uploaded. This was recommended, as all previously saved replays would no longer be viewable after an update due to technical complications. This feature was disabled on November 8th, 2017 after the shutdown of Miiverse.

Contrary to what may be expected, a replay is not saved as a video recording of the match. Instead, each human player's input data, the match's {{s|wikipedia|random seed}}, and the general [[rules]] are saved, so when a replay is watched, the game actually regenerates the match from this data. This makes replays much smaller in file size than a video file, and it also allows for pausing and camera movement during the replay. A side effect of this method, however, is that replays in earlier versions of ''SSB4'' and ''Ultimate'' may become [[desync]]ed due to gameplay changes introduced in the latest update. As there is no way for the current model to combat this, all replays saved before the update will simply become unviewable.

Replays do not save the players'/[[amiibo]]s' names, but this can be changed with some hacks<ref>[http://www.smashboards.com/showthread.php?t=223729 Smash World Forums topic with the code that saves player's names]</ref>. For online battles, the game saves each player's server number and client number. A player will always see themselves as player 1 on their own screen (client), but that may not be true for the server. In saved replays, each player's color and the numbers above the characters' heads indicate the client numbers (the ones that were seen on the screen of the one who saved the replay), whereas the order in which the character portraits appear on the bottom indicate the server numbers.

Replays do not save the input data from CPU players; instead, each CPU player simply replays the match from scratch, which due to the AI's actions being influenced by RNG, results in them reacting to everything the exact same way as long as the RNG seed is the same. The discovery of this discredited a [[List of rumors#Artificial intelligence rumors|rumor]] that the AI was capable of learning, as if this were possible, any replay involving CPUs would desync without having stored each CPU's "learning state".

In ''Ultimate'', replays can also be converted to video files, which are saved to the [[Nintendo Switch]] system's SD card under Nintendo/Album/Extra. Nintendo officially recommends converting replays to videos, as they cannot guarantee replays made before the latest update will function properly. These videos can then be uploaded to [[Shared Content]] and the [[Smash World]] mobile app. Rendered videos can also be transferred to a PC and manually uploaded to a site of the uploader's choice. When converting a replay, the user can choose whether to hide display elements like the [[damage meter]]s, whether to mute the background music and/or sound effects, and whether to use high or normal video quality. The maximum video/replay duration is likely 15-? minutes. The only time a replay won't be allowed to be saved after a match is when a glitch is used to make irregular movement, causing false movement calculations (such as when the player uses the frame by frame option) or if the match is terminated early.

The format for both of these exports are always MP4s at 1280x738+60FPS (1280x720 display) while using the video codec H264 - MPEG-4 AVC (part 10) (avc1), decoded as Planar 4:2:0 YUV and languages are dependent on game language.

The audio sample rate is 48000Hz while using Stereo audio channels, the codec for audio is always MPEG AAC Audio (mp4a) and languages are dependent on game language. Files are organized in the '''Extra''' folder are organized similarly to the Nintendo Switch's '''Album''' directory, where the first folder is '''C6D726972790F87F6521C61FBA400A1DX''', a unique ID for the replay exports from the game, second folder is YY (year), the next folder is MM (month) and the final folder is YY (year), having the file named like: '''YYMMDD-TIMEOFSTART?-C6D726972790F87F6521C61FBA400A1DX''' with the MP4 extension.

 

If the SD Card is low on space, the record pause screen will have a message saying "Remaining amount of time allowed for recording MM:SS", where MM is minutes and SS is seconds.

[[File:3DS replay display bug.png|thumb|The replay menu in SSB4-3DS, in which a bug results in R.O.B.'s head icon not being displayed on the bottom screen.]]