Free Offline Developer, AI & Text Tools

Calculate live tokens for GPT-4o, Claude 3.5, Gemini, DeepSeek, and estimate API call costs.

Visually architect robust system prompts, negative constraints, and few-shot examples for agents.

Instantly fix broken AI JSON, markdown fences, Python booleans, single quotes, and truncated brackets.

Convert prompts between OpenAI, Anthropic, ChatML, and Llama 3 with dynamic variable interpolation.

Build Model Context Protocol (MCP) tool schemas, OpenAI function specs, and TypeScript types.

Visualize document chunking strategies (Recursive, Token, Markdown, Sentence) for vector search.

Build and validate standardized /llms.txt and /llms-full.txt files for AI crawler discovery.

Decode Base64 strings and Data URIs back to downloadable PNG, JPG, WebP, SVG, and GIF images.

Convert Base64 strings into viewable, downloadable PDF documents in an embedded viewer.

Decode Base64 strings to readable plain text and ASCII with full UTF-8 and emoji support.

Convert Base64 audio strings into playable sound in an HTML5 player and download MP3, WAV, and OGG.

Convert Base64 video strings into playable video in an HTML5 player and download MP4/WebM files.

Decode HTTP Authorization: Basic headers to extract usernames, passwords, and API credentials.

Decode Base64 strings into formatted Hexadecimal byte arrays with custom spacing and case.

Reconstruct and download any binary file (ZIP, DOCX, XLSX, PDF, binary) from Base64 strings.

Encode PNG, JPG, SVG, WebP, and GIF images to Base64 Data URIs, HTML img tags, and CSS rules.

Convert PDF documents into clean Base64 encoded strings and Data URIs for REST APIs and storage.

Encode plain text, UTF-8 strings, and emojis into standard and URL-Safe Base64 strings.

Convert MP3, WAV, and OGG sound files into Base64 Data URIs for web inlining and APIs.

Convert MP4 and WebM video clips into Base64 Data URIs to inline video animations into HTML.

Convert raw Hexadecimal byte sequences into compact Base64 strings for REST APIs.

Convert any binary file (ZIP, DOCX, XLSX, PDF) into Base64 strings and Data URIs.

Compare text, JSON payloads, and source code files side-by-side with real-time visual diffing.

Calculate octal numbers (755, 644, 600, 777), symbolic notation (rwxr-xr-x), and copy bash commands.

Clean SVG markup and convert vector icons into React JSX components, Vue templates, and CSS Data URIs.

Calculate netmasks, wildcard masks, usable host IP ranges, and broadcast IPs for VPC & Docker planning.

Generate SHA-256, SHA-512, MD5 hashes and HMAC webhook signatures (Stripe, GitHub) with Web Crypto.

Decode and inspect JSON Web Tokens (JWT) offline without sending private credentials to a server.

Translate 5-field cron schedules into plain English and simulate upcoming execution timestamps across timezones.

Generate time-sortable UUID v7 and ULID batches. Inspect existing UUID v7 to extract embedded creation timestamps.

Convert raw cURL commands from DevTools into clean JavaScript Fetch, Axios, Python Requests, Go, Rust, and PHP.

Diff .env vs .env.example, sort environment variables, check unquoted values, and generate safe templates.

Scrub session cookies, Bearer tokens, and confidential API keys from .har network captures before sharing.

Edit raw GFM Markdown and preview Git READMEs with live HTML in real-time.

Interactive visual side-by-side builder for Markdown documents and Git READMEs.

Create non-expiring QR codes for URLs, WiFi networks, text, and email links with custom colors.

Generate cryptographically secure passwords, memorable Diceware passphrases, and numeric PINs.

Calculate percentages, % increase/decrease, markup, and discount sale prices with step-by-step formulas.

Convert Digital Data (MB/GB/TB), Length, Weight, Temperature, and Time in a live matrix.

Boost daily productivity with 25/5 interval focus timers, audio chimes, checklists, and stopwatches.

Count words, characters, sentences, and paragraphs in real-time.

Free online grammar, spelling, and passive voice checker.

Inspect if a word or phrase reads identically backward as forward.

Convert text to UPPERCASE, lowercase, Title Case, and more.

Repeat any text, word, or emoji up to 10,000 times.

Reverse text, word order, characters, or line sequence.

Instantly find and remove duplicate lines from your text.

Sort text lines alphabetically or by length.

Generate standard dummy placeholder text for website mockups.

Generate random words, sentences, or alphanumeric character strings.

Edit, sync, time-shift, and convert SRT, VTT, and SBV subtitle files with live video preview.