sugarme/tokenizer

NLP tokenizers written in Go language

Go

340

267 commits

updated May 26, 2026

See the code

README

Tokenizer LicenseGo.Dev referenceTravis CIGo Report Card

Overview

tokenizer is pure Go package to facilitate applying Natural Language Processing (NLP) models train/test and inference in Go.

It is heavily inspired by and based on the popular HuggingFace Tokenizers.

tokenizer is part of an ambitious goal (together with transformer and gotch) to bring more AI/deep-learning tools to Gophers so that they can stick to the language they love and build faster software in production.

Features

tokenizer is built in modules located in sub-packages.

  1. Normalizer
  2. Pretokenizer
  3. Tokenizer
  4. Post-processing

It implements various tokenizer models:

  • Word level model
  • Wordpiece model
  • Byte Pair Encoding (BPE)

It can be used for both training new models from scratch or fine-tuning existing models. See examples detail.

Basic example

This tokenizer package is compatible to load pretrained models from Huggingface. Some of them can be loaded using pretrained subpackage.

import (
	"fmt"
	"log"

	"github.com/sugarme/tokenizer/pretrained"
)

func main() {
    // Download and cache pretrained tokenizer. In this case `bert-base-uncased` from Huggingface
    // can be any model with `tokenizer.json` available. E.g. `tiiuae/falcon-7b`
	configFile, err := tokenizer.CachedPath("bert-base-uncased", "tokenizer.json")
	if err != nil {
		panic(err)
	}

	tk, err := pretrained.FromFile(configFile)
	if err != nil {
		panic(err)
	}

	sentence := `The Gophers craft code using [MASK] language.`
	en, err := tk.EncodeSingle(sentence)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("tokens: %q\n", en.Tokens)
	fmt.Printf("offsets: %v\n", en.Offsets)

	// Output
	// tokens: ["the" "go" "##pher" "##s" "craft" "code" "using" "[MASK]" "language" "."]
	// offsets: [[0 3] [4 6] [6 10] [10 11] [12 17] [18 22] [23 28] [29 35] [36 44] [44 45]]
}

All models can be loaded from files manually. pkg.go.dev for detail APIs.

Getting Started

License

tokenizer is Apache 2.0 licensed.

Acknowledgement

deep-learning
golang-tokenizer
nlp
tokenizer

sugarme/tokenizer

NLP tokenizers written in Go language

Go

340

267 commits

updated May 26, 2026

See the code

README

Tokenizer LicenseGo.Dev referenceTravis CIGo Report Card

Overview

tokenizer is pure Go package to facilitate applying Natural Language Processing (NLP) models train/test and inference in Go.

It is heavily inspired by and based on the popular HuggingFace Tokenizers.

tokenizer is part of an ambitious goal (together with transformer and gotch) to bring more AI/deep-learning tools to Gophers so that they can stick to the language they love and build faster software in production.

Features

tokenizer is built in modules located in sub-packages.

  1. Normalizer
  2. Pretokenizer
  3. Tokenizer
  4. Post-processing

It implements various tokenizer models:

  • Word level model
  • Wordpiece model
  • Byte Pair Encoding (BPE)

It can be used for both training new models from scratch or fine-tuning existing models. See examples detail.

Basic example

This tokenizer package is compatible to load pretrained models from Huggingface. Some of them can be loaded using pretrained subpackage.

import (
	"fmt"
	"log"

	"github.com/sugarme/tokenizer/pretrained"
)

func main() {
    // Download and cache pretrained tokenizer. In this case `bert-base-uncased` from Huggingface
    // can be any model with `tokenizer.json` available. E.g. `tiiuae/falcon-7b`
	configFile, err := tokenizer.CachedPath("bert-base-uncased", "tokenizer.json")
	if err != nil {
		panic(err)
	}

	tk, err := pretrained.FromFile(configFile)
	if err != nil {
		panic(err)
	}

	sentence := `The Gophers craft code using [MASK] language.`
	en, err := tk.EncodeSingle(sentence)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("tokens: %q\n", en.Tokens)
	fmt.Printf("offsets: %v\n", en.Offsets)

	// Output
	// tokens: ["the" "go" "##pher" "##s" "craft" "code" "using" "[MASK]" "language" "."]
	// offsets: [[0 3] [4 6] [6 10] [10 11] [12 17] [18 22] [23 28] [29 35] [36 44] [44 45]]
}

All models can be loaded from files manually. pkg.go.dev for detail APIs.

Getting Started

License

tokenizer is Apache 2.0 licensed.

Acknowledgement

deep-learning
golang-tokenizer
nlp
tokenizer

Project health

Overall

4.1/10

Maintained

0/10

Code review

10/10
OpenSSF Scorecard

Latest release

v0.3.0 · Sep 18, 2025

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