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140+ privacy-first tools

All Utilito tools, sorted by category.

A simple directory for calculators, converters, prompt builders, PDF/image utilities, SEO helpers, and developer tools. Big labels, short descriptions, fast filtering.

Showing 140 tools.

Text

11 tools

Color

8 tools

Code

20 tools
{}JSON Formatter

Format, minify, and validate JSON. Catch errors instantly.

🔐Base64 Encode / Decode

Encode text to Base64 or decode Base64 back to text.

🔗URL Encoder / Decoder

Encode or decode URLs and query strings. Handle special characters.

<HTML Entity Encoder

Encode or decode HTML entities. Prevent XSS, display special characters.

.*Regex Tester

Test regular expressions with real-time matching and highlighting.

🎫JWT Decoder

Decode JSON Web Tokens to inspect header, payload, and signature.

🎯JSON Path Tester

Query JSON with simple dot/bracket paths and preview the extracted value.

\String Escape / Unescape

Escape or unescape strings for JSON, JavaScript, HTML, URLs, and regex.

🔁YAML to JSON Converter

Convert simple YAML into pretty-printed JSON in your browser.

🔄JSON to YAML Converter

Convert JSON objects and arrays into readable YAML.

⚙️TOML Formatter / Validator

Format and lightly validate TOML-style config files.

🧾XML Formatter

Format XML with indentation and basic parse-error detection.

📋TSV to CSV Converter

Convert tab-separated values into properly quoted CSV.

🗃️SQL Formatter

Format SQL queries with readable line breaks and indentation.

GraphQL Formatter

Format GraphQL queries, mutations, fragments, and selection sets.

🏷️HTML Formatter

Format HTML markup with indentation for nested tags.

🎛️CSS Formatter

Format CSS rules, declarations, media queries, and nested blocks.

JSON Schema Validator

Validate JSON data against a practical subset of JSON Schema.

.*Regex Generator

Generate regex patterns from positive and negative examples.

🎫JWT Debugger + Editor

Decode and inspect JSON Web Tokens.

Math

15 tools

Generator

12 tools

Security

2 tools

SEO

9 tools

AI

24 tools
🧠Prompt Optimizer

Improve clarity, structure, and effectiveness of AI prompts.

🧩Few-shot Example Generator

Generate high-quality few-shot examples for AI prompts.

Tool Calling Validator

Validate OpenAI and Anthropic function calling JSON structure.

🧱RAG Chunking Strategy Tester

Simulate different chunk sizes for RAG systems.

💬Multi-turn Conversation Simulator

Simulate multi-turn conversations with an AI agent.

📝Evaluation Rubric + Dataset Generator

Generate evaluation rubrics and sample datasets for LLM testing.

🧮Token Counter

Estimate tokens, words, characters, and prompt size for GPT and Claude-style LLM prompts.

💸Prompt Cost Calculator

Estimate LLM API costs from input tokens, output tokens, model pricing, and request volume.

🪟Context Window Calculator

Plan how much prompt, memory, tool output, and response budget fits in an LLM context window.

🧷JSON Prompt Escaper

Escape prompts into JSON-safe strings and unescape JSON strings back into readable text.

💬OpenAI Message JSON Builder

Build valid OpenAI-style chat messages JSON from system, user, and assistant fields.

🟣Anthropic Message JSON Builder

Build Anthropic Messages API JSON from system, user, and assistant fields.

🛠️Tool Schema Generator

Generate a JSON Schema-style function/tool definition from fields and descriptions.

🔁JSON Schema to Tool Definition

Convert a pasted JSON Schema object into OpenAI or Anthropic tool definitions.

🔌MCP Config Generator

Generate MCP server configuration JSON for stdio, HTTP, and environment-variable based servers.

🧾Prompt Diff Tool

Compare two prompt versions and highlight added, removed, and changed lines.

🧭System Prompt Formatter

Clean, structure, and format rough system prompts into consistent sections for agent instructions.

🧼LLM Output Cleaner

Remove common AI wrappers, markdown fences, citations, and extra whitespace from pasted LLM output.

📝Markdown to Chat Messages

Convert a markdown transcript with role headings into chat messages JSON for LLM APIs.

💬Chat Transcript Formatter

Format messy chat logs into clean Markdown, JSON messages, or readable plain text.

📊Eval Dataset JSONL Formatter

Turn prompt and expected-answer rows into JSONL examples for LLM evaluation datasets.

📚Prompt Template Library

Browse, customize, and copy reusable prompt templates for writing, coding, agents, and analysis.

🧱Structured Output Prompt Builder

Build strict JSON-output prompts from a task, schema, examples, and validation rules.

🧭Agent Planning Prompt Builder

Turn a goal, tool list, and constraints into an actionable agent planning prompt.

Developer

4 tools

Image

10 tools

Network

2 tools

File

1 tools

Design

1 tools

Convert

7 tools

Crypto

3 tools

PDF

5 tools

Finance

3 tools

Health

2 tools

Calculator

1 tools