Prompt engineering and evaluation
Draft prompts from templates, track versions, and compare two prompts or two model answers side by side. Build an evaluation set and a judge rubric, test for prompt injection, and check fine-tuning data before you upload it.
17 tools, free, in your browser
Prompt Template Builder
Build AI prompt templates with variables, live preview, and export to JSON/YAML
AI tools
System Prompt Library
Browse and copy curated system prompts for coding, writing, analysis, business, education and creative tasks, searchable by keyword.
AI tools
Prompt Version Diff
Diff two prompt versions line by line, with markers for template variables, XML tags and instruction keywords, plus added variables and token delta.
AI tools
Prompt A/B Test Designer
Plan a prompt A/B test: sample size per variant from a two-proportion z-test with Bonferroni correction, cost, duration and a Markdown plan.
AI tools
System Prompt Editor
Write and analyze AI system prompts with live token counting, variable detection, and XML highlighting
AI tools
System Prompt Analyzer
Estimate a system prompt's tokens for Claude, GPT, Llama and Gemini, its share of a 4K to 200K context window, and its template variables.
AI tools
AI Prompt Tester & Comparator
Compare two to four prompt variants side by side with word-level diffs, token estimates and the {{variables}} each one uses.
AI tools
AI Response Comparator
Compare up to four LLM responses side by side, with line or word diffs and an analysis of length, shared sentences and content unique to each.
AI tools
LLM Output Diff Tool
Compare two to four LLM outputs side by side, diff any pair by line or by word, and compare response length in characters and words.
AI tools
LLM Judge Rubric Builder
Build an LLM-as-judge rubric with weighted criteria on Likert, pass/fail, percentage or 0/1 scales, then export YAML, JSON and a judge prompt.
AI tools
Eval Dataset Builder
Build a golden eval dataset of prompt, expected, category and tag rows, remove duplicates, check category balance, and export to four eval formats.
AI tools
AI Prompt Injection Tester
Check a system prompt's defenses against known injection patterns: role hijacking, instruction override, delimiter abuse, encoding tricks, jailbreaks.
AI tools
AI Guardrail Rule Tester
Write keyword and regex guardrail rules that block, flag or redact text, test them against sample inputs and outputs, and export them as JSON.
AI tools
Fine-Tuning JSONL Validator
Validate OpenAI or Anthropic fine-tuning JSONL row by row for schema, role order, token counts and duplicates, with per-row issues and summary stats.
AI tools
Embedding Similarity Calculator
Compare two embedding vectors by cosine similarity, dot product, Euclidean and Manhattan distance, with dimension hints for common embedding models.
AI tools
Chat Format Converter
Convert chat request JSON between OpenAI Chat Completions, Anthropic Messages, Gemini and Mistral, remapping roles, system prompts, tools and images.
Converters
OpenAI ↔ Anthropic Format Converter
Convert chat messages, tool definitions and responses between the OpenAI and Anthropic API formats in either direction, with format auto-detection.
Converters