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JSON Formatter
Pretty-print, validate and minify JSON with friendly error messages.
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Browse every CoreToolSpace tool
16 free tools, processed locally in your browser. Filter by category or search for something specific.
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JSON to Rust Struct Generator
Turn any JSON into ready-to-compile Rust struct definitions with serde derives.
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JSON to Zod Schema Builder
Turn any JSON into a TypeScript Zod schema with nullable and optional handling.
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JSON to Go Struct Generator
Convert any JSON into Go struct definitions with json tags and pointers for optionals.
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JWT Decoder
Decode JWT header and payload instantly, 100% in your browser — the token never leaves your device.
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CSV to JSON Converter
Convert CSV to JSON with automatic delimiter detection, header handling and real number types, 100% in your browser.
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JSON to CSV Converter
Convert a JSON array or object to CSV with nested objects flattened into dotted columns, ready for Excel or Sheets.
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Base64 Encoder
Encode text to Base64 or decode Base64 back to text, with UTF-8 support, in your browser and never uploaded.
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AI Chatbot Persona Builder
Describe your bot once and get a structured system prompt, sample dialogue, guardrails and a JSON persona card — no prompt-writing experience needed.
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ChaCha20 Encryption
Encrypt text with ChaCha20-Poly1305 into one copyable line. Authenticated, and the passphrase never leaves your browser.
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LLM Token Counter
Count the tokens a prompt will use, and price it against every major model, with the estimate honestly labelled as one.
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System Prompt Optimizer
Find the rules your system prompt never states, drop the padding, and rebuild it into clear sections. No AI API called.
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QR Code Generator
Generate QR codes for URLs, text, WiFi, and vCards.
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JSON to TypeScript Interface Generator
Convert JSON to TypeScript interfaces and types.
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IBAN Validator
Check if an IBAN is valid in seconds. Verifies country code, length and checksum and shows bank code.
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Password Generator
Create strong random passwords or easy-to-remember passphrases. Generated securely.