Terraria separates identity from environment: player characters live in .plr files and worlds live in .wld files. That makes a complete backup a two-part job. Copy both directories, including .bak companions, before editing or moving systems. Steam can independently move individual characters and worlds to cloud storage, so an apparently missing local file may have a counterpart under Steam userdata. SaveEditor.com keeps those locations distinct instead of presenting one universal Terraria save path.
Identify the exact save you intend to edit
The researched Terraria PC save location is Windows: %USERPROFILE%DocumentsMy GamesTerraria
Steam cloud copies may appear under <Steam-folder>userdata<user-id>105600remoteplayers and worlds | macOS: $HOME/Library/Application Support/Terraria/ | Linux / Steam Play: $XDG_DATA_HOME/Terraria/ (normally ~/.local/share/Terraria/). Known file/folder pattern: Players*.plr
Worlds*.wld
*.bak. Storefront context: Steam, GOG Galaxy. Steam can keep cloud-designated player/world files under its userdata remote tree. The normal local Terraria directory still separates Players and Worlds. Do not edit a similarly named file from a different profile, edition, or cloud cache.
Make an untouched backup first
Back up both Players and Worlds plus their .bak files. If a character and world belong together, keep them in the same dated archive even though they are separate files. Keep that copy outside the live save directory and do not overwrite it with later experiments. Cloud context: Steam Cloud and GOG Galaxy are documented. On Steam, cloud movement is enabled per character/world rather than being assumed for every local file. If a launcher can synchronize the save, prevent it from silently replacing either the original or edited copy while testing.
Understand the format boundary
Characters and worlds are separate files: .plr for players and .wld for worlds. Local .bak companions can provide rollback material. Multiplayer characters and worlds should therefore be backed up as separate sets. File-extension context: .plr, .wld, .bak Compatibility note: A world file and a player file have different structures and cannot replace one another. Cloud status can also differ per file. These facts help identify the save but do not automatically reveal every field, checksum, encryption rule, or version-specific structure inside it.
Use only a Tool whose claim matches the file
Generic viewers and diff tools can inspect bytes without claiming game-specific semantics. A game-specific editor should be used only when its Tool page explicitly lists Terraria, a matching supported version/container, and a Verified operational runtime. A planned URL or Game Hub is not evidence that an editor exists.
Test the edited copy safely
Write to a new output file when the Tool supports it, keep the original backup, restore the edited copy into the correct profile/storefront location, and launch the game only after the file operation finishes. If the game rejects it, If a character or world is missing, check both the local directory and Steam remote location. Before using a .bak copy, preserve the current .plr/.wld and the backup so the recovery remains reversible. Return to the untouched backup before trying another change.
Verification context: Windows/macOS/Linux locations, .plr/.wld patterns, Steam remote paths, and per-item Steam cloud behavior were reviewed against current PCGamingWiki coverage.