Aksharav0.5.0

Benchmarks

Fewer tokens at every vocabulary size

Bytes per token on 41 held-out test sets, against 31 published tokenizers. Akshara is shown at nine sizes, each the first merges of one training run, so every comparison can be made at a matched vocabulary.
Score against vocabulary size bytes per token, higher is better
  • Akshara at each size
  • Published tokenizers
2.53.03.54.04.55.05.532k49k59k92k120k151k200k248k448kVocabulary size (log scale)Akshara 32kAkshara 49kAkshara 59kAkshara 92kAkshara 120kAkshara 151kAkshara 200kAkshara 248kAkshara 448kGemma 3 / Gemma 4o200k_baseMistral-Large-4-1T-A52Bsarvam-105b †Mistral-Nemo-Base-2407LFM3-1.7BFalcon-H1-34B-InstructLlama-3.2-1BKimi-K3Hy3GLM-5.3-FlashERNIE-4.5-21B-A3B-PTcl100k_basep50k_base †SmolLM2-135M †Phi-3.5-mini-instruct †gpt2 †
Matched vocabulary sizes Akshara minus the published tokenizer, bytes per token
Each published tokenizer is paired with the largest Akshara size whose vocabulary is no more than 2% larger; tokenizers with no such size are left out. Green: Akshara is ahead; red: Akshara is behind.
Published tokenizerVocabularyAksharaOverallEnglishCode avgLanguages avg
Phi-3.5-mini-instruct †32,011Akshara 32k+0.76+0.05+0.38+1.85
SmolLM2-135M †49,152Akshara 49k+1.00−0.24+0.46+2.77
gpt2 †50,257Akshara 49k+1.25−0.35+1.19+2.92
OpenAI p50k_base (Codex) †50,281Akshara 49k+0.99−0.35+0.40+2.91
cl100k_base (GPT-4, OLMo-2, Olmo-3, phi-4)100,277Akshara 92k+0.85−0.13−0.09+2.77
ERNIE-4.5-21B-A3B-PT101,304Akshara 92k+0.70+0.16+0.41+1.54
Hy3120,818Akshara 120k+0.78−0.05+0.15+2.24
LFM3-1.7B125,033Akshara 120k+0.53+0.03+0.25+1.32
Llama-3.2-1B128,256Akshara 120k+0.67−0.04−0.04+2.08
DeepSeek-V3128,815Akshara 120k+0.55−0.08+0.24+1.48
Mistral-Nemo-Base-2407131,072Akshara 120k+0.43+0.10+0.27+0.93
GLM-5.3-Flash154,856Akshara 151k+0.92+0.03+0.01+2.71
Kimi-K3163,840Akshara 151k+0.84+0.03+0.06+2.43
OpenAI o200k_base (GPT-4o)200,019Akshara 200k+0.39+0.05+0.10+1.02
Mistral-Large-4-1T-A52B204,800Akshara 200k+0.45+0.18+0.23+0.93
North-Micro-Vision-Instruct255,033Akshara 248k+0.50−0.05+0.07+1.48
Falcon-H1-34B-Instruct261,120Akshara 248k+1.01+0.31+0.74+1.97
sarvam-105b †262,144Akshara 248k+0.68+0.19+0.49+1.37
Gemma 3 / Gemma 4 tokenizer262,144Akshara 248k+0.43+0.18+0.48+0.63

At or above 151k, Akshara matches or beats every same-size published tokenizer on all three groups, except on English against North-Micro-Vision-Instruct at 248k (−0.05).

Best tokenizer per test set bytes per token
Test setAkshara, by vocabulary sizeBest other tokenizerOpenAI GPT-4o (o200k_base)
448k248k200k151k120k92k59k49k32kTokenizerScoreScore448k uses fewer
Averages
Overall score5.415.145.034.884.754.594.324.203.93gemma-3-1b-it4.714.6414%
Code average4.083.993.953.893.853.783.663.603.45North-Micro-Vision-Instruct3.923.856%
Languages average7.216.596.356.025.745.424.914.704.24gemma-3-1b-it5.975.3326%
English
English web4.944.844.794.724.664.564.394.314.09North-Micro-Vision-Instruct4.894.744%
Code
Python4.364.274.234.174.134.053.913.853.69North-Micro-Vision-Instruct4.224.165%
JavaScript4.134.064.033.983.953.883.763.703.57Llama-3.2-1B4.043.984%
TypeScript4.404.294.244.174.124.053.883.843.71North-Micro-Vision-Instruct4.214.205%
Java4.724.634.584.514.464.394.264.204.05Llama-3.2-1B4.584.495%
C#5.044.944.884.814.764.684.554.474.29Llama-3.2-1B4.924.805%
C++4.003.933.893.843.813.753.633.583.42North-Micro-Vision-Instruct3.923.883%
C3.573.503.473.433.393.343.253.203.08Llama-3.2-1B3.393.366%
Go3.733.653.613.573.533.483.373.323.20North-Micro-Vision-Instruct3.593.526%
Rust4.384.324.294.244.194.124.003.943.79North-Micro-Vision-Instruct4.244.165%
PHP4.043.953.923.883.843.783.683.633.50Llama-3.2-1B3.973.952%
Ruby4.214.154.114.064.013.953.833.773.62North-Micro-Vision-Instruct4.154.054%
Swift4.824.714.674.604.544.464.314.234.07Llama-3.2-1B4.604.467%
Kotlin4.774.634.574.494.434.364.224.163.97Llama-3.2-1B4.634.525%
Dart4.294.224.194.144.114.043.933.883.74GLM-5.3-Flash4.214.153%
Lua3.863.753.713.653.583.523.403.353.22North-Micro-Vision-Instruct3.663.626%
R3.223.143.113.043.012.962.862.822.72North-Micro-Vision-Instruct3.143.065%
SQL3.623.543.503.423.373.293.123.022.83North-Micro-Vision-Instruct3.503.367%
Bash/Shell3.633.533.493.433.373.313.183.112.98North-Micro-Vision-Instruct3.513.368%
PowerShell4.254.134.073.993.943.863.723.653.50North-Micro-Vision-Instruct3.933.7512%
HTML/CSS3.843.793.763.723.683.633.513.433.25North-Micro-Vision-Instruct3.703.587%
Assembly2.742.682.642.602.572.532.452.402.29North-Micro-Vision-Instruct2.562.509%
Languages
German4.203.943.843.713.603.453.213.122.90North-Micro-Vision-Instruct3.873.7012%
French4.604.354.254.123.993.833.593.503.27MiniMax-M2.54.384.1011%
Spanish4.834.584.474.324.194.033.763.663.41MiniMax-M2.54.664.3710%
Russian7.386.766.516.195.935.625.124.904.42Falcon-H1-34B-Instruct6.486.0818%
Chinese5.104.734.614.444.294.123.783.673.37Qwen3.8-27B4.623.4432%
Japanese5.935.475.315.094.904.694.354.183.85MiniMax-M2.55.333.5340%
Korean4.554.174.043.873.733.573.283.172.90North-Micro-Vision-Instruct4.303.5921%
Arabic7.216.586.336.035.755.454.954.764.33Falcon-H1-34B-Instruct6.735.7321%
Urdu6.375.975.795.555.345.074.594.363.95gemma-3-1b-it5.595.2518%
Hindi9.208.498.177.797.396.966.316.095.45gemma-3-1b-it9.067.6217%
Marathi9.938.968.588.047.597.086.366.085.43sarvam-19.147.0129%
Gujarati8.627.757.446.956.606.195.595.334.73sarvam-105b7.466.4925%
Bengali11.6910.5610.079.398.818.237.186.786.02gemma-3-1b-it11.377.6634%
Tamil10.979.829.388.848.337.816.986.645.90sarvam-19.757.3733%
Telugu9.238.207.847.336.966.475.775.514.91sarvam-17.796.2732%
Thai12.3610.9210.439.669.038.367.346.966.09Qwen3.8-27B10.686.8644%
Vietnamese4.994.874.804.704.584.444.164.003.59North-Micro-Vision-Instruct4.794.2515%
Turkish4.924.474.314.073.903.703.333.202.92Mistral-Large-4-1T-A52B3.963.7823%
Indonesian4.994.644.494.294.113.903.573.433.12North-Micro-Vision-Instruct4.734.0818%
Same vocabulary size Akshara cut to each group's smallest vocabulary
The distinct benchmarked tokenizers grouped by vocabulary size. In each group Akshara is cut to the group's smallest vocabulary and compared on every measure. Select a group to see its chart.
VocabularyAkshara sizeCompared withAksharaBest otherOverallAhead byMeasures led
32,0004 tokenizers3.93Mamba-Codestral-7B-v0.13.26+20%40 of 44
49,0006 tokenizers4.20pythia-160m3.49+20%41 of 44
59,0008 tokenizers4.32Falcon-H1-3B-Instruct3.63+19%30 of 44
92,0007 tokenizers4.59ERNIE-4.5-21B-A3B-PT3.89+18%24 of 44
120,00013 tokenizers4.75Mistral-Nemo-Base-24074.31+10%20 of 44
151,0007 tokenizers4.88Seed-OSS-36B-Instruct4.11+19%34 of 44
200,0004 tokenizers5.03OpenAI o200k_base (GPT-4o)4.64+8%37 of 44
248,0008 tokenizers5.14gemma-3-1b-it4.71+9%36 of 44

200k group: Akshara 200k and 4 tokenizers, overall score