How to use this developer tool
- Paste TypeScript or upload a .ts/.tsx file.
- Select a checking profile.
- Choose the rules to apply.
- Run the checker and review line-numbered diagnostics.
#113 · Programming Language Developer Tool
TypeScript Checker
Check TypeScript for unbalanced delimiters, unterminated strings or comments, duplicate declarations, broad types, assertions, and common typing issues without a project setup.
Developer Input
Browser-based source processingitems
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What this developer tool does
The checker provides fast structural and style checks with line-aware diagnostics. It does not replace the official TypeScript compiler or project-level type checking.
Stateful lexical scan → delimiter validation → declaration extraction → type-pattern rules → line-aware diagnostic report.
Compiler-dependent inference is labeled heuristic. Use tsc for authoritative project compilation.
Example
Input:
interface User {
name: string;
}
function getUser(id: any) {
return id;
}Expected use: Run the selected mode and review the generated output and statistics.Tips for better output
- Use Strict for exported library code.
- Explicit any warnings can be disabled for migration work.
- TSX syntax receives lightweight structural checks only.
- Verify final code with the official TypeScript compiler.
FAQ
How can I check TypeScript code without installing TypeScript?
Paste the code and run this browser-based structural checker for immediate diagnostics.
How do I find explicit any types in TypeScript?
Enable Flag explicit any to list each occurrence with its source line.
How can I detect duplicate TypeScript interfaces?
Enable duplicate declaration checks to compare interface, type, enum, and class names.
How do I check missing return types in TypeScript?
Enable Check return types to flag functions that appear to lack explicit return annotations.
How can I find unclosed brackets in TypeScript code?
The lexical scanner validates parentheses, brackets, and braces while ignoring strings and comments.
Related developer tools
Supported analysis and output
| Module | Purpose |
|---|---|
| Input | Local browser processing |
| Analysis | Tool-specific lexical and structural logic |
| Output | Copy and download ready |
| Privacy | No upload or server execution |