Precise tools for the AI engineer.
Twelve sharp utilities for the AI engineer: token counting, cost math, prompt scaffolds, format utilities. Every tool runs in your browser. Your prompts never leave this tab.
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Put the cost calculator on your site.
A free embeddable widget with always-current pricing for all 52 models. One paste, zero maintenance, no tracking of your readers.
Reads & Comparisons
All Notes →Grok 4 vs GPT-5
Pricing, context, reasoning, and when to pick each. Live data.
PromptPerfect Alternative
PromptPerfect sunsets September 2026. Where to take your workflow next.
How I cut my OpenAI API bill 73% in a weekend
Three specific levers (prompt caching, batch API, and model routing) that cut a real produ...
Claude Sonnet 4.6 vs GPT-5: I ran 200 prompts. Here's what won.
An apples-to-apples comparison of Claude Sonnet 4.6 and GPT-5 across coding, summarization...
AI Tools
SECTION 01/03 · 5 TOOLSToken Counter
Count tokens for GPT-5, Claude, Gemini, Grok & 50+ LLMs. Real tokenizer ratios.
LLM Cost Calculator
Compare API costs across 50+ models from 7 providers. August 2026 verified pricing.
AI Model Comparison
Compare 50+ models side-by-side: pricing, context, speed, vision & reasoning.
AI Prompt Generator
Generate optimized prompts for any LLM with tone & format controls.
System Prompt Builder
Build structured system prompts with role, rules & output format.
Dev Tools
SECTION 02/03 · 5 TOOLSJSON Formatter
Format, validate & minify JSON data. Error detection included.
Base64 Encoder/Decoder
Encode & decode Base64 strings instantly.
UUID Generator
Generate UUID v4 identifiers in bulk.
Epoch Converter
Convert Unix timestamps to dates and back.
Cron Expression Generator
Build cron expressions visually with presets.