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FUTO Notes

What FUTO Notes syncs: file types, size limit and name rules

FUTO Notes sync carries two kinds of files: markdown notes (.md) and images. Every other file in your notes folder stays on the device it is on, and sync doesn’t report it.

Notes you create in the app always follow the rules below. They matter mostly for files that other apps put in the notes folder, for example a folder you copied in from another notes app.

Files that sync

  • Notes: files ending in .md. The extension must be lowercase, so Note.MD doesn’t sync.
  • Images with one of these extensions, in any case: jpg, jpeg, png, gif, webp, svg, bmp, ico, avif, heic.
  • Folders, as part of the path of the notes and images inside them.

Each file’s name and folder path are encrypted along with its contents, so the server never sees them.

Files that don’t sync

  • Other file types: PDFs, .txt, .tiff, .heif, archives, audio and video, and anything else not listed above.
  • Hidden files and folders: any name that starts with a dot, and everything inside a folder whose name starts with a dot, such as .obsidian or .git.
  • Symbolic links.
  • Empty folders. A folder reaches other devices only once it holds a note or image.
  • App settings. Each device keeps its own.

Size limit

The server accepts up to 100 MiB per encrypted file. The limit is fixed and can’t be configured.

Notes are plain text and won’t come close. Images are converted to text (base64) before they are encrypted, which makes them about a third larger, so the largest image that syncs is about 75 MiB. An image over the limit stays on the device it is on.

A reverse proxy in front of the server can set a much smaller limit. See large notes or images never arrive.

Name and folder rules

Sync has to work across Linux, macOS, Windows, iOS and Android, so it follows the strictest rules of all of them.

NameWhat happens
Contains < > : " | ? * or a control character, in the file name or any folder name above itDoesn’t sync to or from any device. The file stays where it is.
Starts with a dotHidden. Doesn’t sync.
Starts or ends with a space, or ends with a dotSyncs. Other devices save it with the spaces and dots trimmed.
A Windows reserved name: CON, PRN, AUX, NUL, COM1 to COM9, LPT1 to LPT9, in any case and with any extensionSyncs. Other devices add an underscore, so CON.md becomes CON_.md.
More than 10 folders deepUploads, but other devices refuse it and report “Sync completed with errors. Some changes could not reach the server.”
A file or folder name longer than 255 bytesSame as above. 255 bytes is 255 plain English letters, but fewer accented letters, and fewer still for Chinese, Japanese, Korean or emoji.
Differs from another name only in upper and lower case, such as Ideas.md and ideas.mdBoth sync. On other devices, the one uploaded later gets a suffix, such as ideas (conflict 01a0cd10).md. See same-name notes.

In the app, a note title can’t contain < > : " / \ | ? *, can’t start or end with a dot, and can be at most 200 characters.

Note text must be UTF-8

Notes are read as UTF-8 text. A .md file in another encoding can’t be uploaded, and each sync reports “Sync completed with errors. Some changes could not reach the server.” until you convert the file to UTF-8 or remove it.

Next steps