Category

Developer Tools

Utilities for API mocking, webhooks, environment files, logs, and local development workflows.

17 toolsNo signupBrowser-first

Validate environment variables

Use this category when you need a quick result without opening a heavy app or creating an account.

Analyze logs and mock API responses

Use this category when you need a quick result without opening a heavy app or creating an account.

Test webhook and developer integration flows

Use this category when you need a quick result without opening a heavy app or creating an account.

Recommended paths

Useful developer workflows

Validate app configuration before deploy

Check environment files, JSON schemas, regexes, and scheduled jobs in one pass.

Environment Variable Validator JSON Schema Validator Regex Tester Cron Expression Parser

Debug API and webhook integrations

Mock responses, test webhook payloads, inspect headers, and analyze logs.

API Mock Generator Webhook Tester HTTP Header Checker Log File Analyzer

Format developer data safely

Clean common config/data formats before copying them into code reviews or tickets.

JSON Formatter YAML Formatter / Validator TOML Formatter / Validator XML Formatter

RAG and agent context prep

Prepare retrieval snippets and debug logs for AI-assisted development by cleaning Markdown, trimming logs, checking token counts, and sizing the final context window.

RAG Chunking Strategy Tester Log Context Trimmer Markdown Cleaner / Link Stripper Token Counter Context Window Calculator

How to use this category

Start with one of the highlighted tools, paste or enter only the data needed for the task, then copy the result into your own workflow. Each tool page explains its assumptions and limits where they matter.

Privacy and quality note

Most tools in this category run in the browser and are designed for fast utility work without accounts, uploads, or dark patterns.

Start here

Popular developer tools

Cron Expression Parser

Parse cron expressions and see the human-readable schedule.

Agent Regression Pack Workbench

Validate, sanitize, version, diff, and export named agent fixture packs without execution.

Send test requests to webhook URLs and view responses.

Log File Analyzer

Analyze logs for errors, warnings, and patterns.

Directory

All developer tools

Cron Expression Parser

Parse cron expressions and see the human-readable schedule.

Agent Regression Pack Workbench

Validate, sanitize, version, diff, and export named agent fixture packs without execution.

Send test requests to webhook URLs and view responses.

Log File Analyzer

Analyze logs for errors, warnings, and patterns.

Environment Variable Validator

Validate .env files for required variables and format.

API Mock Generator

Generate simple mock JSON responses for API endpoints.

User-Agent Parser

Parse browser, OS, device type, engine, and bot signals from any user-agent string.

HTTP Status Codes

Search and explore HTTP status codes with meanings, common causes, and retry guidance.

MIME Type Explorer

Search MIME types and file extensions with common uses, HTTP Content-Type guidance, and upload notes.

Convert common curl requests into fetch, Node, and Python snippets with honest flag caveats.

Cron Expression Explainer

Explain 5-field cron expressions with next-run previews, typed errors, and scheduler dialect warnings.

Unified Diff & Apply-Patch Workbench

Parse, preview, and apply unified diffs locally with exact file, hunk, and line conflict evidence.

Mermaid Syntax Validator

Preflight common Mermaid diagram syntax locally with bounded line and column diagnostics.

Vega-Lite Spec Validator

Validate Vega-Lite JSON structure locally with actionable schema-path and parse diagnostics.

Web Page QA & Accessibility Preflight

Audit pasted HTML, accessibility, metadata, links, and response headers locally with stable evidence.

Bulk File Renamer

Preview and generate rename commands for multiple files.

SVG Path Optimizer

Simplify and clean SVG path data.

Developer tools FAQ

Are developer tools browser-only?

Most are browser-first. Tools that contact public URLs or APIs disclose the network behavior.

Can I export reports?

Many developer utilities include copyable reports or generated snippets; more export options are being added over time.

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