Tools
Free AI developer tools built by ToolBrain. All client-side — nothing leaves your browser. No signup, no API keys, no cost.
Token Counter
Count tokens across GPT, Claude, DeepSeek, and Llama tokenizers. Paste text, see counts instantly.
Prompt Optimizer
Analyze your prompts, auto-rewrite them, and browse the template library. 3 client-side tools in one: analyzer, rewriter, and template library.
Variable Extractor
Extract {{variables}} from prompt templates. See counts, spot duplicates, and fill in test values.
Context Window Calculator
Compare context windows, plan budgets, analyze batches, and project monthly API costs — all 4 tools in one.
Model Benchmark Registry
Compare model benchmark results — track which models (DeepSeek V4 Flash, Groq Llama 3.3 70B, Cerebras gpt-oss-120b) win which task types.
Prompt Version Diff
Compare prompt versions with word-level diff highlighting. Save version history to localStorage, diff any two, export/import as JSON.