Code Analyzer & Quality Checker

Analyze your code for common mistakes and best practices. Rule-based static checker for Javascript, HTML, and CSS. 100% local.

Findings

No analysis performed yet.

What is the Code Analyzer & Quality Checker?

The Code Analyzer & Quality Checker is a client-side static code analysis utility designed to inspect JavaScript, HTML, and CSS source code for errors, formatting issues, and security vulnerabilities. By scanning source scripts against a local rule database, you can audit your codebase instantly without external linting configurations.

This checker processes all script analyses locally inside your browser's private memory. Because no source codes, variable structures, or logic definitions are uploaded to external databases, your proprietary codebases and algorithms remain strictly confidential.

How to Use the Code Analyzer & Quality Checker

  1. Select Programming Language: Choose the language format (JavaScript, HTML, or CSS) from the language dropdown menu in the sidebar.
  2. Paste Your Source Code: Paste your raw code string into the "Code Input" textarea editor.
  3. Run the Analysis: Click the "Analyze Code" button to trigger the local rule-checking scripts.
  4. Inspect Findings: Review the summary metrics and detailed findings listed in the right panel. Findings are categorized by severity levels (such as Error, Warning, or Info).
  5. Clear the Editor: Click the "Clear" button to empty the editor and reset findings for your next script.

Key Features

  • Multi-Language Rule Sets: Performs custom audits for JavaScript syntax, HTML tags, and CSS style declarations.
  • Vulnerability Detection: Flags security issues such as insecure eval() functions or dangerous innerHTML assignments.
  • Semantic Quality Flags: Identifies unused variables, duplicate declarations, and missing image alt tags.
  • Categorized Severity Reports: Groups findings into critical errors, warnings, and style hints to prioritize debugging.
  • 100% Offline Static Audits: Runs analysis logic entirely in browser RAM to safeguard your source code.

Common Use Cases

  • Pre-Commit Sanity Checks: Scan code snippets for syntax errors or left-over console logs before submitting pull requests.
  • Accessibility Auditing: Inspect HTML pages for missing accessibility attributes, document outlines, and form labels.
  • CSS Specificity Reviews: Check stylesheet classes for rule overrides, broken declarations, and layout smells.
  • Secure Sandbox Audits: Review code snippets containing proprietary corporate algorithms or database queries privately.

Frequently Asked Questions

This tool is designed for high-speed, configuration-free sanity checks. It does not replace comprehensive build linters like ESLint, but it offers a convenient way to inspect snippets quickly without installing dependencies.

No. 99tool.in processes all static analysis, pattern matching, and error reporting locally. Your source code never leaves your computer and is wiped from memory when you close the tab.

The parser flags syntax errors, unused variables, duplicate keys, unsafe expressions (like eval() or document.write()), and unfinished statements.

Using !important breaks the natural CSS cascade, making overrides and stylesheets difficult to debug. The analyzer flags it to encourage managing selectors using specificity hierarchies.

The findings list provides detailed explanations and line references for each issue. You can easily find the corresponding lines in the code input panel to make corrections.

🔒 Privacy & Data Note: Code analysis and rule checks are processed locally in your browser. No source code or configuration data is sent to our servers.