Limits and timeouts

This page lists the numbers Floe holds a transfer to, what happens when one is reached, and the page that explains each. Sizes are binary: 2 GB means 2,147,483,648 bytes.

The short version

Floe sets no size limit on a direct transfer, and caps a relayed one at 2 GB. A room code works for 10 minutes at most, a share link works while its sender is connected, and a room holds two devices. A request link takes one drop of at most 10,000 files.

Transfer size

The one size limit Floe sets on purpose is on relayed connections. The other rows come from the receiving device, or from how the protocol or a ZIP archive writes a size.

Limit	Value	At the limit
A transfer over a direct connection	No limit from Floe	Nothing in Floe stops it. What runs out first is the receiving disk or the receiving browser. See File size limits.
A transfer, or one request-link drop, over a relayed connection	2 GB in total. Exactly 2 GB passes and 1 byte more does not	The sender checks once, before any file data moves, and sends nothing. On a request link the receiving Floe Desktop also stops a drop at the file that would pass 2 GB. See File size limits.
What a browser can receive	Set by the browser and the device, not by Floe	The transfer stops and the page says the browser ran out of memory. Floe Desktop and the CLI save straight to disk and have no such ceiling. See Known limitations.
The archive a browser’s Download ZIP makes	At most 4,294,967,294 bytes, 2 bytes under 4 GB: the files, plus 92 bytes and the file’s name twice for each file, plus 22 bytes. At most 65,534 files	The page reads no file and shows “ZIP creation failed. Try “Download All” instead.” Download All still saves every file. See Troubleshooting.
One file saved to a FAT or FAT32 drive by Floe Desktop or `floe receive` on Windows	4,294,967,295 bytes, which is 1 byte under 4 GB	The receive stops before any of that file is written. `floe receive` prints `receive stopped: a file is larger than the save drive can hold`. See floe receive.
The size a sender can announce for one file, or for a whole batch	9,007,199,254,740,991 bytes (`2^53 - 1`)	The receiver refuses the file’s description and the transfer stops. See Transfer protocol.

Files and paths

Floe Desktop and floe receive check where each file would be saved before they write anything. A browser keeps what it receives inside the browser, so of these rows only the first and the last three apply to it.

Limit	Value	At the limit
Files in one transfer by room code or share link	No limit from Floe	Nothing stops it. A request-link drop is the exception. See Request link limits.
Folder depth of a file’s path inside the transfer	32 levels: 31 folders and the file	The receive stops before that file is written, the sender is told, and files saved before it are kept. `floe receive` prints `receive stopped: a file's path is too deep or too long to save in this folder`. See floe receive and Receiving files.
Length of that path	235 characters for most names. Most emoji count as 2	The same stop. See the same two pages.
One file or folder name, for `floe receive` on macOS or Linux	255 bytes, a limit of the file system. A long name in Chinese, Japanese or Korean can pass the 235-character check and still exceed it	The receive stops, and `floe receive` prints `write error: could not finish writing a file, so it was not kept`.
A path that starts at a drive or a root, such as `C:\x` or `/x`	Never accepted	The same stop as for a path too deep. See the same two pages.
Files with the same name in one save folder	100,000: the name itself, then `name (1).ext` up to `name (99999).ext`	The receive stops, and `floe receive` prints `write error: could not finish writing a file, so it was not kept`. Nobody meets this by accident.
A file’s name with its folder path, as the sender announces it	It has to fit, with the rest of the file’s description, in one 1,000-byte message	Every receiver stops the receive and tells the sender. `floe receive` prints `rejected the sender's control message: 1204 bytes, limit 1000`, with the real size. A request link’s page and `floe send --to` check first and send nothing. See Transfer protocol.
A file name shown on screen	200 characters	A longer name is shortened on screen, with its extension kept. Floe Desktop and the CLI do not shorten the name the file is saved under. See floe receive.
A file or folder name a browser saves, or puts in a ZIP	200 characters	A longer name is shortened, with its extension kept.

A receiving browser words the 1,000-byte stop as “The sender sent a control message larger than 1000 bytes, so the transfer was stopped.”

Codes, links and rooms

Limit	Value	At the limit
How long a room code works	At most 10 minutes. It stops sooner when the receiver joins, when the room empties, or when the sender registers a new code	The code is not found. `floe receive` prints `code "olive-tiger-castle" not found: it was already used, the sender left, or it expired (a code lasts 10 minutes at most)`. See How a transfer works.
Words in a room code	3, drawn from a list of 1,247	After 10 draws in a row that collide with a live code, the server issues a code of 4 words. See Architecture.
How long a share link works	No time limit	It works for as long as its room exists, which is while the sender stays connected. After that `floe receive` and Floe Desktop say `this code or link is no longer active; ask the sender for a new one`. See How a transfer works.
Devices in one room	2: one sender and one receiver	A third device is turned away. The browser shows “Link Invalid” and `floe receive` prints `room is full (someone else may already be receiving)`. See How a transfer works.
Networks that can use one room	2. One network is one IPv4 address, or one IPv6 /64	Once devices on two networks have exchanged connection-setup messages in a room, a device on a third network is turned away the same way, for as long as the room exists. See How a transfer works.

Request link limits

One drop through a request link is held to more than a transfer by room code or share link.

Limit	Value
Drops per link	1, then the link is used up
Links open at a time	1 in each Floe Desktop
Link lifetime	30 minutes, 1 hour, 8 hours, 24 hours (the default), 3 days or 7 days
Label	64 characters
Time to answer a request	9 minutes 45 seconds
Files per drop	10,000
Size of a direct drop	No limit set by Floe
Size of a relayed drop	2 GB
Largest file on a FAT or FAT32 save drive	4 GB minus 1 byte
Longest one drop may run	24 hours
Free space	Each file is taken only if 2 GB would still be free after saving it; otherwise the drop stops
Free space after an Auto-accept drop	20 GB or a tenth of the drive, whichever is larger; a drop that would leave less asks first
Folder depth and path length	About 235 characters of path, and 32 levels (31 folders and a file), as for every receive in Floe Desktop and the CLI
New links from one network	20 in any 24 hours
Open links from one network	10 at a time

Floe Desktop enforces every row but the last two, which the signaling server enforces. Floe Desktop closes a link once its drop ends, and for 24 hours after that the server turns away anyone who tries it. The server also ends a link that is still open 7 days and 10 minutes after it was made. What each limit looks like when it is reached is in Request links, and the server’s side is in Turn on request links. How long the server holds a link whose PC is offline, and how long it remembers a used or ended link, is in Architecture.

Timeouts

Each row is a wait that ends a step when it runs out. The CLI and Floe Desktop run the same engine, so they share these waits and word the result differently.

Wait	Limit	When it runs out
The server assigning a role after the CLI or Floe Desktop joins a room	20 seconds	`timed out waiting for the server to assign a role` in the CLI, “Can’t reach the server” in Floe Desktop. See Troubleshooting for Floe Desktop, and Transfer protocol.
The other device’s offer or answer	30 seconds	`timed out waiting for the peer's offer` or `timed out waiting for the peer to answer` in the CLI, “Both people need Floe open at the same time” in Floe Desktop. See Troubleshooting for the CLI and Troubleshooting for Floe Desktop.
The connection being established	30 seconds, then 10 seconds more for the data channel	`timed out establishing a connection`, or `connected but the data channel did not open` for the last 10 seconds, in the CLI. “Couldn’t connect the two devices” in Floe Desktop. See Troubleshooting for the CLI and Troubleshooting for Floe Desktop.
The receiver accepting each file	120 seconds	The send fails: `timed out waiting for ack` in the CLI, “Transfer timed out waiting for receiver. Please try again.” in the browser. See Troubleshooting for the CLI and Troubleshooting for the browser.
A browser sender getting back into its room after its connection to the server returned	About 1 minute: six tries over 59 seconds	The status “Reconnecting to your link” gives way to a red banner, “This link stopped working. Reload the page, add the files again, and share the new link.”. See Troubleshooting.
The owner of a request link answering a request	9 minutes 45 seconds. The sender waits 10 minutes 15 seconds	Only that request ends, and the link keeps waiting. The sender sees “They did not answer in time. Nothing was sent.”. See Request links.
The server answering a join through a request link	10 seconds	“Request links are not available on this Floe server.”. See Troubleshooting.
A request link’s page reaching Floe’s server after Send	20 seconds	“Couldn’t connect to their computer. Nothing was sent.” See Sending through a request link.
The two computers connecting once the server has let a request link’s page in	75 seconds	The same message.
A request link’s page trying again after its last attempt left the room closed	Up to 45 seconds, a try every 3 seconds	The page stays on “Connecting to their computer” meanwhile, then reads “This link has already been used”. See Sending through a request link.
A sender on a request link announcing its first file	30 seconds after it connects	That sender is dropped and the link waits again, with “The sender couldn’t connect”. See Troubleshooting.
First data after the devices connect, in `floe receive` and Floe Desktop	30 seconds	`connected, but no data arrived from the sender within 30s` in the CLI, “The sender never started sending” in Floe Desktop. See Troubleshooting.
No progress in the middle of a transfer, in the CLI and Floe Desktop	60 seconds	The transfer fails, and a receiver deletes the file it was writing. See Transfer protocol.
The receiver confirming delivery to `floe send` or Floe Desktop	No fixed limit. A receiver that vanished is given up on about 30 seconds after its last packet	`the connection closed before the receiver confirmed delivery` in the CLI. See Troubleshooting.
A browser working out a file’s SHA-256	At most 45 seconds after the file’s last byte when sending. At most 90 seconds when receiving with more files to come	The file is still kept, without the SHA-256 mark. See File checks.
The CLI or Floe Desktop fetching relay details, or a room code	30 seconds	Without relay details the transfer goes on with no relay, and one that was told to use only the relay stops. Without an answer for a code, `floe receive` fails and `floe send` shows its link alone. See Transfer protocol.
Reporting the byte count after a receive	5 seconds	The report is dropped. The files are not affected. See Transfer protocol.
`floe` cleaning up after Ctrl+C	5 seconds	It exits anyway, and a `.part` file can remain. See floe receive.
`floe update` asking GitHub for the newest release, then fetching `checksums.txt`, then the archive	10 seconds, 30 seconds and 5 minutes	The update stops and the installed `floe` is unchanged. See Update the CLI.
`floe version` asking GitHub for the newest release, when it has no saved answer	1 second	No update hint is printed. See The update check.
Floe Desktop’s update check	10 seconds	No update notice is shown, the same as when there is nothing new. See Check for updates.

Server limits

A signaling server counts the first five rows for each network address, over the last 60 seconds, and the sixth for each address as it stands now. The values are the built-in defaults. A self-hosted server can change the ones that name a setting in Configuration, which also explains how an address is counted.

Limit	Value	At the limit
New connections	30 per address per 60 seconds	The connection is refused. A refused attempt is not counted, so the next one succeeds once earlier connections are 60 seconds old. See Configuration.
Requests for relay credentials	20 per address per 60 seconds	The server answers `429`. See Configuration.
Requests to make or look up a room code	60 per address per 60 seconds	The server answers `429`. See Configuration.
Failed room code lookups	10 per address per 60 seconds	The server answers `429`, whatever code was asked for. See Configuration.
Byte-count reports	60 per address per 60 seconds. This one has no setting	The server answers `429` and the count is not added. See Configuration.
Open connections	60 per address at a time	The connection is refused, as one over the new-connection limit is. A refused attempt is not counted, so the next one succeeds once another connection from that address has closed. See Configuration.
Room codes held at once	10,000	Making a code answers `503`. `floe send` goes on with its link alone. See Troubleshooting.
One byte-count report	5,497,558,138,880 bytes (5 TiB)	The server answers `400` and the count is not added. See Configuration.
One message to the server on either signaling connection	1,000,000 bytes	A `/ws` connection is closed with code `1009`. See Architecture.
One connection-setup message passed to the other device	65,536 characters by the server’s own count, nested at most 8 levels deep. How the server counts, and why some characters cost more, is in What the server relays, and what it drops	The message is dropped with no answer. See Architecture.
One HTTP request body	102,400 bytes	The server answers `413`. See HTTP API.

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Limits and timeouts

The short version

Transfer size

Files and paths

Codes, links and rooms

Request link limits

Timeouts

Server limits

​The short version

​Transfer size

​Files and paths

​Codes, links and rooms

​Request link limits

​Timeouts

​Server limits

The short version

Transfer size

Files and paths

Codes, links and rooms

Request link limits

Timeouts

Server limits