← WIZ
// EXPERIMENTS
✦ FABLE 5.1 · 1M EXAMPLE · 2026-09-13
🧠

Explore a 1M-token context window

Add books and code to an estimated token budget. Leave room for instructions, tool results and output.

📖 Historical article: Sonnet 4.6, two experiments, one got personal (February 2026) →
Context Window Used0 / 1M tokens (0.0%)
0250K500K750K1M
⚡
Harry Potter series
1,084,170 words (all 7 novels)

Seven novels. Approximate English word count, converted using the assumption below.

Estimated: 1,445,560 tokens

Fits 0 in 1M context144.6% each
💍
Lord of the Rings
~473K words (trilogy)

The trilogy only, excluding The Hobbit. Approximate English word count.

Estimated: 630,968 tokens

Fits 1 in 1M context63.1% each
📚
War and Peace
~580K words

Approximate English word count. Translation and edition change the total.

Estimated: 773,334 tokens

Fits 1 in 1M context77.3% each
📖
The Bible
~783K words

Old and New Testament. Approximate English word count; the estimated tokens exceed 1M.

Estimated: 1,044,183 tokens

Fits 0 in 1M context104.4% each
💬
WhatsApp messages
~15 tokens avg per message

One short message. An illustrative budget; length and language vary.

Estimated: 15 tokens

Fits 66,666 in 1M context<1% each
📧
Work emails
~200 tokens avg per email

One medium email. An illustrative budget, without attachments.

Estimated: 200 tokens

Fits 5,000 in 1M context<1% each
📹
Meeting transcripts
~8K tokens per 1-hour meeting

A meeting transcript. An illustrative text budget, excluding audio.

Estimated: 8,000 tokens

Fits 125 in 1M context<1% each
🎙️
Podcast episodes
~20K tokens per hour (transcript)

A long podcast transcript. An illustrative text budget, excluding audio.

Estimated: 20,000 tokens

Fits 50 in 1M context2.0% each
🐧
Large repository example
Illustrative code budget, 2026-09-13

A synthetic large repository budget, not a measured Linux release.

Estimated: 25,000,000 tokens

Fits 0 in 1M context2500.0% each
⚛️
React core
135,812 characters · 2026-09-13

React v19.2.0, packages/react: 52 JavaScript files, excluding __tests__. Measured source characters, estimated tokens.

Estimated: 33,953 tokens

Fits 29 in 1M context3.4% each
🐍
Python stdlib
11,899,763 characters · 2026-09-13

CPython v3.13.0, Lib: 695 Python files, excluding Lib/test. Measured source characters, estimated tokens.

Estimated: 2,974,941 tokens

Fits 0 in 1M context297.5% each
🚀
Startup codebase
Illustrative code budget, 2026-09-13

A synthetic small project budget. Excludes build output, dependencies and images.

Estimated: 200,000 tokens

Fits 5 in 1M context20.0% each
📓
Daily journal entries
~500 tokens per day (medium entry)

One journal entry. An illustrative budget for a few paragraphs.

Estimated: 500 tokens

Fits 2,000 in 1M context<1% each
🌍
Wikipedia articles
~1.5K tokens avg per article

One article. An illustrative text budget, not a sampled Wikipedia average.

Estimated: 1,500 tokens

Fits 666 in 1M context<1% each
📰
News collections
50K-token illustrative collection

One collection of news articles. An illustrative budget, not all global coverage.

Estimated: 50,000 tokens

Fits 20 in 1M context5.0% each
🌙
Bedtime stories (for Filip)
~600 tokens per story (~450 words)

One short story. About 450 English words under the same estimate.

Estimated: 600 tokens

Fits 1,666 in 1M context<1% each
✍️
750,000
words
Approximate word equivalent of 1M tokens
💾
~4 MB
plain text
At 4 ASCII characters per token; encoding changes byte size
⏱️
41.7 hrs
to read
Time for an average reader at 300 wpm

What the budget tells you: A larger window can hold more source text. It still needs room for your instructions, tool results and output. Test whether the model uses the details your task depends on.

Source releases: React v19.2.0 · CPython v3.13.0

Estimates assume 0.75 English words per token, or 4 characters per token for source text. Actual tokenization varies by model, language and content.

Book word counts are approximate inputs, not measured token counts. React core and Python stdlib use source characters counted on 2026-09-13. Other entries are illustrative budgets, not measured corpus sizes.