Developer Tools — Free Online Utilities
Free online tools for developers and AI users. LLM token counter, API cost calculator, JSON formatter, and more. No registration required.
AI Stack Builder — Find Your Perfect LLM + Vector DB + …
Answer 5 questions about your project and get a matched AI stack recommendation: LLM (GPT-4o / Claude / Gemini / Llama), …
Open Tool →Hreflang Tags Generator — Multi-Language & International SEO
Generate valid hreflang tags for multi-language sites in seconds. Paste your language → URL pairs and get …
Open Tool →LLM API Cost Calculator — GPT-4, Claude, Gemini
Calculate LLM API monthly cost. Enter your input/output tokens, requests per day, and pick a model — get instant cost …
Open Tool →LLM Recommender — Which Model Should You Actually Use?
Answer a few questions about your use case, budget, and priorities, and get a matched LLM recommendation — GPT-4o, …
Open Tool →LLM Token Counter — GPT-4, Claude, Gemini Tokenization …
Free online LLM token counter. See how OpenAI GPT-4/GPT-4o, Anthropic Claude, and Google Gemini tokenize your text, side …
Open Tool →llms.txt Generator — Help AI Crawlers (ChatGPT, Claude, …
Generate a valid llms.txt file in seconds. Help AI crawlers like ChatGPT, Claude, and Perplexity understand your site …
Open Tool →MCP Tool Builder — Generate Model Context Protocol Server …
Generate a working MCP (Model Context Protocol) server skeleton from a plain description of what it should do. Pick a …
Open Tool →Meta Tags Generator — SEO Title, Description, Open Graph & …
Generate copy-paste-ready HTML head meta tags from one simple form: SEO title, description, canonical, Open Graph, and …
Open Tool →OG Card Preview — Facebook / Twitter / LinkedIn Social Share …
Live preview how your link looks when shared on Facebook, Twitter, LinkedIn, and Slack. Paste a URL or fill in OG meta …
Open Tool →Prompt Optimizer — Trim Filler, Cut Tokens, Keep Meaning
Paste a raw prompt and get a tightened version — filler words and redundant instructions stripped, token count reduced, …
Open Tool →Robots.txt Generator — Control AI Crawlers (GPTBot, …
Generate a valid robots.txt in seconds, with explicit rules for AI crawlers — GPTBot, ClaudeBot, PerplexityBot, and more …
Open Tool →Schema.org Generator — JSON-LD Structured Data for Rich …
Generate valid JSON-LD structured data for Article, FAQPage, Product, HowTo, and more — copy-paste ready for Google rich …
Open Tool →Top 10 Free MCP Tools in 2026: Best Model Context Protocol …
The 10 best free MCP servers for Claude, Cursor, and any MCP-compatible AI client — filesystem, web search, memory, …
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