AI Tools
Token counters, prompt utilities, schema helpers, and JSONL validators for AI builders.
LLM Token Counter
Estimate prompt tokens, characters, words, and rough model budget before sending text to an AI model. Runs in your browser with no account required.
AI ToolsLLM API Cost Calculator
Estimate AI API spend from input tokens, output tokens, and common model pricing presets. Runs in your browser with no account required.
AI ToolsContext Window Checker
Check whether a prompt is likely to fit within a selected model context window. Runs in your browser with no account required.
AI ToolsPrompt Diff Checker
Compare two prompt versions line by line before shipping a prompt change. Runs in your browser with no account required.
AI ToolsJSON Schema Builder
Generate a starter JSON Schema from sample JSON for structured AI outputs and validation. Runs in your browser with no account required.
AI ToolsJSONL Validator
Validate JSONL datasets line by line for AI fine-tuning, evaluation, and data pipelines. Runs in your browser with no account required.
AI ToolsInvisible Character Cleaner
Remove zero-width and hidden Unicode characters from prompts, copy, and pasted text. Runs in your browser with no account required.