JQL Validator

The JQL Online Validator analyzes a provided JQL string to confirm syntactic correctness and structural validity. It tokenizes the input, applies Jira's JQL grammar, and reports exact positions of syntax issues rather than generic messages. This helps Jira admins, developers, and automation engineers catch mistakes before they run a search or save a filter. It accepts standard JQL constructs such as field comparisons, logical operators, parentheses, and a subset of functions like now() and startOfDay(). It does not query Jira systems or fetch data; it only validates syntax.
Conceptually, a query is parsed into tokens and an abstract syntax representation. The validator performs lexical analysis, parses the expression against a JQL grammar, and validates field names against a known set of Jira fields. It checks operator validity, function invocation, and parentheses balance. When issues are found, it emits structured diagnostics with the offending token position, a descriptive message, and an optional suggested correction. Advanced rules cover nested expressions and a subset of Jira functions while staying within standard JQL.
Use cases include pre-flight validation for dashboards, CI pipelines, and teaching materials. The tool reduces debugging time by providing precise feedback, enabling teams to craft correct filters and reliable reports. Its value lies in actionable diagnostics that mirror Jira’s parser behavior while remaining agnostic to specific instance configurations or permissions.