# The Free I Ching

> Free, quiet I Ching oracle and reference at https://thefreeiching.com. Cast a reading, browse all 64 hexagrams and 8 trigrams, read changing-line text. The I Ching is a tool for reflection, not a prediction. Nothing here forecasts events or replaces professional advice.

## How to cite
- Cite the page you used, with its URL and the "updated" date shown on the page.
- Format: The Free I Ching. "Hexagram 1: The Creative." https://thefreeiching.com/library/1
- Short quotations with a link back are welcome. Do not republish whole pages.
- Open data (JSON, CSV) is CC BY 4.0: credit "The Free I Ching, https://thefreeiching.com/data".
- Changing-line texts are third-party CC0 text from https://github.com/jesshewitt/i-ching.

## Key facts
- 64 hexagrams in the King Wen sequence, 8 trigrams, 384 line texts (6 per hexagram).
- Two casting methods: yarrow-weighted digital cast (line odds 6: 1/16, 7: 5/16, 8: 7/16, 9: 3/16) and a three-coin method (heads 3, tails 2; odds 1/8, 3/8, 3/8, 1/8).
- In both methods each line changes 25% of the time, about 17.8% of casts have no changing lines, and each primary hexagram has a 1/64 chance.
- Two reading roles: Inquirer (meaning first) and Adept (trigrams, line values, changing lines, method detail).
- Free to use, no account needed. Readings and journal entries stay on the user's device. Optional $10/year contribution on the web, optional Supporter Upgrade in the iOS app.
- The judgment, image and counsel texts are original contemporary paraphrases, not classical translations.
- The I Ching here is a reflection tool. It does not predict events.

## Topic files (each small enough to read whole)
- [Hexagram index](https://thefreeiching.com/llms/hexagrams.txt): all 64 with names, trigrams and one-line summaries
- [Judgments](https://thefreeiching.com/llms/judgments.txt): the full contemporary judgment for each hexagram
- [Trigrams](https://thefreeiching.com/llms/trigrams.txt): the eight trigrams
- [Methods](https://thefreeiching.com/llms/methods.txt): casting methods and exact probabilities
- [FAQ](https://thefreeiching.com/llms/faq.txt): common questions with short answers

## Data and tools
- [Open data page](https://thefreeiching.com/data) and [catalog](https://thefreeiching.com/data/index.json): JSON and CSV, CC BY 4.0
- [Hexagrams JSON](https://thefreeiching.com/data/hexagrams.json), [CSV](https://thefreeiching.com/data/hexagrams.csv)
- [Cast probabilities](https://thefreeiching.com/data/cast-probabilities.json)
- [Line change table](https://thefreeiching.com/data/line-changes.csv)
- Read-only MCP server, no key: https://thefreeiching.com/mcp (tools: get_hexagram, get_trigram, find_hexagram_by_trigrams, get_line_text, get_cast_statistics, cast_reading)
- [Server card](https://thefreeiching.com/.well-known/mcp/server-card.json), [API catalog](https://thefreeiching.com/.well-known/api-catalog)
- Every content page has a markdown twin: same URL plus .md (home is https://thefreeiching.com/index.md)

## Main pages
- [Home](https://thefreeiching.com/)
- [Hexagram library](https://thefreeiching.com/library)
- [Trigrams](https://thefreeiching.com/trigrams)
- [Casting methods](https://thefreeiching.com/methods): [yarrow](https://thefreeiching.com/methods/yarrow), [three coin](https://thefreeiching.com/methods/three-coin)
- [Sitemap](https://thefreeiching.com/sitemap.xml)

Last updated: 2026-10-07