is a number set up to be unique to a particular Wolfram System session.


$SessionID
is a number set up to be unique to a particular Wolfram System session.
Details

- $SessionID should be different for different Wolfram System sessions run either on the same computer or on different computers.
- The value of $SessionID is based on $MachineID, as well as AbsoluteTime[] and operating system parameters such as the Wolfram System process ID.
Examples
Basic Examples (1)
See Also
$ModuleNumber $ProcessID $KernelID $FrontEndSession CreateUUID
Function Repository: SessionInformation
Tech Notes
Related Guides
History
Introduced in 1991 (2.0)
Text
Wolfram Research (1991), $SessionID, Wolfram Language function, https://reference.wolfram.com/language/ref/$SessionID.html.
CMS
Wolfram Language. 1991. "$SessionID." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/$SessionID.html.
APA
Wolfram Language. (1991). $SessionID. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/$SessionID.html
BibTeX
@misc{reference.wolfram_2025_$sessionid, author="Wolfram Research", title="{$SessionID}", year="1991", howpublished="\url{https://reference.wolfram.com/language/ref/$SessionID.html}", note=[Accessed: 15-August-2025]}
BibLaTeX
@online{reference.wolfram_2025_$sessionid, organization={Wolfram Research}, title={$SessionID}, year={1991}, url={https://reference.wolfram.com/language/ref/$SessionID.html}, note=[Accessed: 15-August-2025]}