✦ Private browser tools for humans + agents

Utility tools,

A fast, privacy-first toolbox with calculators, converters, prompt builders, PDF/image utilities, and developer helpers— no accounts, no uploads, no clutter.

140+ tools Runs locally Built for agents too

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Popular Tools

{}JSON Formatter .*Regex Tester 🎫JWT Decoder 🔐Base64 Encode / Decode ✍️Markdown Preview 🔑Password Generator 🎨Color Converter 📝Word Counter ▦QR Code Generator 🆔UUID Generator 🗜️Image Compressor 📎PDF Merger

All tools140 tools available

Count words, characters, sentences, and paragraphs.

Convert text to UPPER, lower, Title, camelCase, snake_case, and more.

Lorem Ipsum Generator

Generate placeholder text in paragraphs, sentences, or words.

Compare two texts and see the differences highlighted.

Markdown Preview

Write Markdown and see the rendered HTML output in real time.

Convert titles and text into SEO-friendly URL slugs.

Reading Time Calculator

Estimate reading time, speaking time, word count, and character count for any text.

Duplicate Line Remover

Remove duplicate lines from text while preserving order or sorting unique values.

Sort lines alphabetically, numerically, by length, ascending or descending.

Remove Empty Lines

Remove blank lines, whitespace-only lines, or compact text into a clean line list.

Whitespace Normalizer

Normalize spaces, tabs, line breaks, and smart whitespace in pasted text.

Color Converter

Convert between HEX, RGB, HSL, and CMYK. Pick a color to start.

Palette Generator

Generate color palettes from a base color. Shades, tints, and complements.

Gradient Generator

Build CSS gradients visually. Linear and radial. Copy the CSS.

Contrast Checker / WCAG

Check foreground/background color contrast against WCAG AA and AAA text guidelines.

CSS Box Shadow Generator

Build CSS box-shadow styles visually and copy the generated CSS.

CSS Border Radius Generator

Generate border-radius CSS with linked or independent corner controls.

CSS Button Generator

Design a CSS button with colors, padding, radius, font weight, and hover styles.

CSS Glassmorphism Generator

Create frosted glass UI CSS with blur, opacity, border, and shadow controls.

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.

Test regular expressions with real-time matching and highlighting.

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.

Format XML with indentation and basic parse-error detection.

TSV to CSV Converter

Convert tab-separated values into properly quoted CSV.

Format SQL queries with readable line breaks and indentation.

GraphQL Formatter

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

Format HTML markup with indentation for nested tags.

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

JSON Schema Validator

Validate JSON data against a practical subset of JSON Schema.

Time Duration Calculator

Calculate the exact duration between two dates and times.

Quickly calculate tip amount and total bill.

Discount Calculator

Calculate sale price and savings from a discount percentage.

File Size Converter

Convert between Bytes, KB, MB, GB, and TB instantly.

Data Transfer Time Calculator

Estimate download/upload time based on file size and speed.

Random Name Generator

Generate realistic first + last name combinations.

Domain Name Generator

Generate brandable .com domain name ideas from keywords.

Meta Description Generator

Generate SEO-friendly meta descriptions from a page title and topic.

License Generator

Generate common open source license text (MIT, Apache 2.0, GPL-3.0, BSD).

README Template Generator

Generate a clean, professional README.md template for your project.

Password Strength Checker

Check password strength and get improvement suggestions.

Regex Generator

Generate regex patterns from positive and negative examples.

Schema.org JSON-LD Generator

Generate structured data markup for Article, Product, FAQ, and Organization.

Prompt Optimizer

Improve clarity, structure, and effectiveness of AI prompts.

SSL Certificate Checker

Check domain SSL certificate details and get guidance.

Send test requests to webhook URLs and view responses.

Image Color Palette Extractor

Extract dominant colors from an image.

Keyword Density Checker

Analyze word frequency and keyword density in text.

JWT Debugger + Editor

Decode and inspect JSON Web Tokens.

Look up A, AAAA, MX, TXT, and CNAME records for a domain.

Bulk File Renamer

Preview and generate rename commands for multiple files.

Few-shot Example Generator

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

Tool Calling Validator

Validate OpenAI and Anthropic function calling JSON structure.

Core Web Vitals Auditor

Quick self-audit checklist for LCP, FID, and CLS.

SVG Path Optimizer

Simplify and clean SVG path data.

Retirement / FIRE Calculator

Project how long your savings will last with different withdrawal rates.

Crypto Tax Estimator

Estimate capital gains on crypto trades using FIFO method.

RAG Chunking Strategy Tester

Simulate different chunk sizes for RAG systems.

Internal Linking Suggestion Tool

Find internal linking opportunities in your content.

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.

Multi-turn Conversation Simulator

Simulate multi-turn conversations with an AI agent.

BlurHash Generator

Generate BlurHash placeholders from images.

Evaluation Rubric + Dataset Generator

Generate evaluation rubrics and sample datasets for LLM testing.

Convert length, weight, temperature, volume, and more.

Unix Timestamp Converter

Convert Unix timestamps to human-readable dates and vice versa.

Number Base Converter

Convert between binary, octal, decimal, and hexadecimal.

CSV to JSON Converter

Paste CSV data and convert it to a JSON array instantly.

JSON to CSV Converter

Convert a JSON array of objects into downloadable CSV.

CSV to Markdown Table

Convert CSV data into a clean Markdown table.

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text.

Generate UUID v4 tokens. One or many at once.

Password Generator

Generate strong random passwords with custom length and character sets.

Username Generator

Generate unique usernames with styles, keywords, numbers, and availability-friendly variants.

Business Name Generator

Generate brandable business, startup, product, and project names from keywords.

Hashtag Generator

Generate social media hashtags from topics, keywords, and captions.

Robots.txt Generator

Generate robots.txt rules for crawlers, sitemaps, disallowed paths, and crawl delay.

Gitignore Generator

Generate .gitignore files for popular languages, frameworks, editors, and operating systems.

QR Code Generator

Create QR codes for URLs, text, email, phone, SMS, and Wi-Fi.

Image Compressor

Compress JPG, PNG, and WebP images in your browser.

Resize images by width, height, percentage, or preset sizes.

Image Converter

Convert images between PNG, JPG, and WebP locally in your browser.

Crop images by dragging a crop box or using common aspect ratios.

Favicon Generator

Generate favicon PNG sizes and an HTML snippet from one image.

Image to Base64

Convert images to Base64 data URLs for CSS, HTML, and APIs.

Base64 to Image

Decode Base64 image strings and data URLs into downloadable images.

Merge multiple PDF files into one combined PDF in your browser.

Extract selected pages or page ranges from a PDF.

PDF Page Remover

Remove unwanted pages from a PDF and download the cleaned file.

Rotate all pages or selected pages in a PDF by 90, 180, or 270 degrees.

PDF Metadata Viewer

View PDF page count, title, author, subject, creator, producer, and dates.

Meta Tag Checker

Paste HTML and audit title, meta description, canonical, robots, viewport, and social tags.

Open Graph Preview

Preview and generate Open Graph and Twitter/X card tags for social sharing.

SERP Snippet Preview

Preview how a page title, URL, and meta description may look in Google search results.

Robots.txt Tester

Test whether a URL path is allowed or blocked by pasted robots.txt rules.

Build campaign tracking URLs with utm_source, utm_medium, utm_campaign, and more.

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.

Percentage Calculator

Calculate percentages, percentage change, and percentage of a number.

Cron Expression Parser

Parse cron expressions and see the human-readable schedule.

Calculate age in years, months, days, and total days from a birth date.

Date Difference Calculator

Calculate the time between two dates in days, weeks, months, and years.

Loan Calculator

Estimate monthly payment, total interest, and total cost for a loan.

Compound Interest Calculator

Project investment growth with contributions, interest rate, and compounding.

Aspect Ratio Calculator

Calculate proportional width, height, and common aspect ratios for images and video.

Mortgage Calculator

Calculate monthly mortgage payments with taxes, insurance, PMI, and amortization.

Currency Converter

Convert between major currencies using editable approximate exchange rates.

Calorie / Macro Calculator

Estimate daily calories, TDEE, and protein/fat/carbohydrate macro targets.

Subnet Calculator

Calculate CIDR subnet ranges, netmask, broadcast address, and usable hosts.

Estimate federal income tax, FICA, effective rate, and take-home pay.

Scientific Calculator

Evaluate arithmetic, trig, logs, exponents, roots, constants, and expression history.

Invoice Generator

Create a simple printable invoice with line items, tax, discounts, and totals.

Calculate weighted GPA from courses, credits, grades, and custom grade scales.

Random Number / Sequence Generator

Generate random integers, decimals, sequences, and shuffled lists with constraints.

BMI / Health Calculator

Calculate BMI, category, healthy weight range, and simple health metrics.

Utility Cost Estimator

Estimate monthly electricity, gas, water, internet, and household utility bills.

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.