TokenAtlas 🌐

Universal Multilingual Tokenizer Benchmark & Global Inflation Atlas

TokenAtlas is an open-source benchmarking engine and diagnostic suite that measures the token inflation tax across global languages and frontier LLM tokenizers using Meta's FLORES-200 parallel evaluation corpus.

⚡ The Problem: The Hidden Token Tax

Large Language Model tokenizers (like BPE, Tiktoken, and WordPiece) are trained predominantly on English datasets. Expressing the exact same thought in other languages requires significantly more tokens.

This creates 4 compounding penalties for international users:

1. Financial Tax: APIs bill strictly per token. Multilingual conversations cost up to $4\times$ more per 1k words.
2. Context Shrinkage: A 128k context window is effectively cut to ~30k words for high-inflation languages.
3. TTFT Latency Penalty: Attention prefill latency scales with sequence token length.
4. VRAM Footprint: Paged KV-cache memory allocators must reserve more physical blocks per user session.

🚀 Quickstart

Installation

pip install token-atlas-engine

1. Compare Tokenizers on Single String

token-atlas compare --text "ここでテキストを分かち書きします" --tokenizers gpt-4o,gpt-4 --language ja

2. Run Multilingual Parallel Benchmark

# Benchmark all 28 languages across models
token-atlas bench --tokenizers gpt-4o,gpt-4 --languages all --samples 5

# Benchmark with custom parallel corpus JSON
token-atlas bench --tokenizers deepseek-v3,mistral-tekken --custom-corpus my_corpus.json

3. Compare Text from File or String

token-atlas compare --file document.txt --tokenizers gpt-4o,mistral-tekken --language kn

4. Tokenizer-Aware Model Routing (Cut Effective Costs)

# Analyze prompt script and recommend the most token-efficient model
token-atlas route --text "ದಯವಿಟ್ಟು ಈ ದಾಖಲೆಯನ್ನು ವಿಶ್ಲೇಷಿಸಿ ಮತ್ತು ಕನ್ನಡದಲ್ಲಿ ವರದಿ ನೀಡಿ"

5. Lossless Prompt Token Minification (Save 15-35% on Bills)

# Minify prompt whitespace and embedded JSON schemas before model dispatch
token-atlas minify --file agent_prompt.txt --out minified_prompt.txt

6. Benchmark Multi-Domain Inflation (Code, Indentation, Tools, Math)

# Benchmark tool-calling schema tax (verbose vs compact JSON)
token-atlas bench-domain --domain tools --tokenizers gpt-4o,gpt-4

# Benchmark indentation tax (4-space vs 2-space vs tabs vs minified)
token-atlas bench-domain --domain indentation --tokenizers gpt-4o,gpt-4

# Benchmark cross-language code syntax
token-atlas bench-domain --domain code --tokenizers gpt-4o,gpt-4

7. Diagnose UTF-8 Byte Fragmentation

token-atlas explain-bytes --text "ಕನ್ನಡ"

8. Python Production API

from token_atlas import recommend_model, minify_prompt

# 1. Route to the most cost-effective model for the detected script
decision = recommend_model(
    prompt="ದಯವಿಟ್ಟು ಈ ದಾಖಲೆಯನ್ನು ವಿಶ್ಲೇಷಿಸಿ...",
    budget_tier="frugal"
)
print(f"Recommended: {decision.recommended_model} ({decision.savings_vs_worst} cheaper)")

# 2. Minify prompt whitespace and embedded JSON losslessly
minified = minify_prompt(raw_prompt)
print(f"Saved {minified.tokens_saved} tokens ({minified.token_reduction_pct}% reduction)")

9. Export Standalone Interactive Web Atlas

token-atlas export-web --out-dir docs/

10. List Supported Tokenizers & Language Families

token-atlas list-tokenizers
token-atlas list-tokenizers --category code
token-atlas list-languages

🌐 Interactive Web Atlas & Live Demo

TokenAtlas exports a zero-dependency, self-contained interactive web application with:

• Real-time sorting and filtering by language family and token inflation index.
• Cross-model head-to-head comparison table.
• Live Token Tax & Context Shrinkage Calculator with interactive preset prompts.

Live GitHub Pages Deployment: prajwal7-2002.github.io/token-atlas

📚 Educational Guide: How Tokenizers Work

For a first-principles breakdown of Byte-Pair Encoding (BPE), UTF-8 byte fallback mechanics, and the vocabulary VRAM scaling equation ($V \times d_{\text{model}}$), see: 👉 docs/learn-tokenizers.md

📊 Core Metrics

TokenAtlas rigorously evaluates 4 dimensions on identical parallel sentences:

• Token Inflation Index ($\tau$):
  $$\tau(L, M) = \frac{\text{Tokens in Language } L}{\text{Tokens in English}}$$
• Bytes Per Token (BPT): Compression density of information per token ($BPT = \text{Bytes} / \text{Tokens}$).
• Effective Context Window ($W_{\text{eff}}$): Real usable context in equivalent English tokens ($W_{\text{eff}} = \text{ContextLimit} / \tau$).
• Cost Multiplier ($\kappa$): Financial invoice scaling factor per 1k semantic words.

🔬 Evaluated Frontier Tokenizers

🌍 Supported Language Coverage (52 Languages)

TokenAtlas evaluates 52 global languages across 12 linguistic families aligned to FLORES-200:

• Germanic & Romance: English (en), German (de), Dutch (nl), Swedish (sv), Danish (da), Norwegian (no), French (fr), Spanish (es), Italian (it), Portuguese (pt), Romanian (ro)
• Slavic: Russian (ru), Ukrainian (uk), Polish (pl), Czech (cs), Bulgarian (bg), Serbian (sr), Croatian (hr)
• Hellenic & Finno-Ugric: Greek (el), Finnish (fi), Hungarian (hu)
• Semitic & Middle Eastern: Arabic (ar), Hebrew (he), Amharic (am), Persian (fa)
• Turkic: Turkish (tr), Azerbaijani (az), Uzbek (uz), Kazakh (kk)
• Indic (Indo-Aryan): Hindi (hi), Bengali (bn), Marathi (mr), Urdu (ur), Gujarati (gu), Punjabi (pa), Nepali (ne), Sinhala (si)
• Indic (Dravidian): Kannada (kn), Tamil (ta), Telugu (te), Malayalam (ml)
• CJK: Simplified Chinese (zh), Traditional Chinese (zh-tw), Japanese (ja), Korean (ko)
• Southeast Asian & Austronesian: Vietnamese (vi), Thai (th), Indonesian (id), Malay (ms), Filipino (tl)
• African: Swahili (sw), Yoruba (yo)

🛠️ Developer Setup & Testing

# Clone repository
git clone https://github.com/Prajwal7-2002/token-atlas.git
cd token-atlas

# Run test suite
uv run pytest

📜 Citation

If you use TokenAtlas in your research or benchmarks, please cite:

@software{Pujari_TokenAtlas_2026,
  author = {Pujari, Prajwal},
  title = {{TokenAtlas: Universal Multilingual Tokenizer Benchmark & Global Inflation Atlas}},
  year = {2026},
  url = {https://github.com/Prajwal7-2002/token-atlas},
  license = {Apache-2.0}
}

License

Apache 2.0 © 2026 Prajwal Pujari. See LICENSE for details.