FastBertTokenizer 0.5.18-alpha

This is a prerelease version of FastBertTokenizer.

There is a newer version of this package available.
See the version list below for details.

dotnet add package FastBertTokenizer --version 0.5.18-alpha

NuGet\Install-Package FastBertTokenizer -Version 0.5.18-alpha

This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.

<PackageReference Include="FastBertTokenizer" Version="0.5.18-alpha" />

For projects that support PackageReference, copy this XML node into the project file to reference the package.

<PackageVersion Include="FastBertTokenizer" Version="0.5.18-alpha" />
                    

                            Directory.Packages.props

<PackageReference Include="FastBertTokenizer" />
                    

                            Project file

For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.

paket add FastBertTokenizer --version 0.5.18-alpha

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

#r "nuget: FastBertTokenizer, 0.5.18-alpha"

#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.

#:package FastBertTokenizer@0.5.18-alpha

#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.

#addin nuget:?package=FastBertTokenizer&version=0.5.18-alpha&prerelease
                    

                            Install as a Cake Addin

#tool nuget:?package=FastBertTokenizer&version=0.5.18-alpha&prerelease
                    

                            Install as a Cake Tool

The NuGet Team does not provide support for this client. Please contact its maintainers for support.

FastBertTokenizer

A fast and memory-efficient library for WordPiece tokenization as it is used by BERT. Tokenization correctness and speed are automatically evaluated in extensive unit tests and benchmarks.

Goals

Enabling you to run your AI workloads on .NET in production.
Correctness - Results that are equivalent to HuggingFace Transformers' AutoTokenizer's in all practical cases.
Speed - Tokenization should be as fast as reasonably possible.
Ease of use - The API should be easy to understand and use.

Getting Started

dotnet new console
dotnet add package FastBertTokenizer

using FastBertTokenizer;

var tok = new BertTokenizer();
await tok.LoadFromHuggingFaceAsync("bert-base-uncased");
var (inputIds, attentionMask, tokenTypeIds) = tok.Encode("Lorem ipsum dolor sit amet.");
Console.WriteLine(string.Join(", ", inputIds.ToArray()));
var decoded = tok.Decode(inputIds.Span);
Console.WriteLine(decoded);

// Output:
// 101, 19544, 2213, 12997, 17421, 2079, 10626, 4133, 2572, 3388, 1012, 102
// [CLS] lorem ipsum dolor sit amet. [SEP]

example project

Comparison to BERTTokenizers

about 1 order of magnitude faster
allocates more than 1 order of magnitude less memory
better whitespace handling
handles unknown characters correctly
does not throw if text is longer than maximum sequence length
handles unicode control chars
handles other alphabets such as greek and right-to-left languages

Note that while BERTTokenizers handles token type incorrectly, it does support input of two pieces of text that are tokenized with a separator in between. FastBertTokenizer currently does not support this.

Logo

Created by combining https://icons.getbootstrap.com/icons/cursor-text/ in .NET brand color with https://icons.getbootstrap.com/icons/braces/.

Product	Compatible and additional computed target framework versions.
.NET	net6.0 is compatible. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 was computed. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 is compatible. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. net9.0 was computed. net9.0-android was computed. net9.0-browser was computed. net9.0-ios was computed. net9.0-maccatalyst was computed. net9.0-macos was computed. net9.0-tvos was computed. net9.0-windows was computed. net10.0 was computed. net10.0-android was computed. net10.0-browser was computed. net10.0-ios was computed. net10.0-maccatalyst was computed. net10.0-macos was computed. net10.0-tvos was computed. net10.0-windows was computed.

Product

.NET

Compatible target framework(s)

Included target framework(s) (in package)

Learn more about Target Frameworks and .NET Standard.

net6.0
- No dependencies.
net8.0
- No dependencies.

NuGet packages (6)

Showing the top 5 NuGet packages that depend on FastBertTokenizer:

Package	Downloads
Microsoft.SemanticKernel.Connectors.Onnx Semantic Kernel connectors for the ONNX runtime. Contains clients for text embedding generation.	216.6K
SmartComponents.LocalEmbeddings Experimental, end-to-end AI features for .NET apps. Docs and info at https://github.com/dotnet-smartcomponents/smartcomponents	158.7K
McpEngramMemory.Core Cognitive engram memory engine with semantic search, knowledge graphs, clustering, lifecycle management, and hierarchical expert routing (HMoE). Core library for MCP Engram Memory.	805
ADCenterSpain.Infrastructure.AI Common classes for AI development	614
WinInsider.Microsoft.SemanticKernel.Connectors.Onnx.DirectML Semantic Kernel connector for Microsoft.ML.OnnxRuntimeGenAI targeting DirectML	515

GitHub repositories (1)

Showing the top 1 popular GitHub repositories that depend on FastBertTokenizer:

Repository	Stars
microsoft/semantic-kernel Integrate cutting-edge LLM technology quickly and easily into your apps	27.7K

Version	Downloads	Last Updated
1.1.30-alpha	2,635	3/3/2025
1.0.28	556,756	4/30/2024
0.5.18-alpha	1,395	12/21/2023
0.4.67	192,054	12/11/2023
0.3.29	471	9/18/2023
0.2.7	261	9/14/2023

https://github.com/georg-jung/FastBertTokenizer/releases/tag/v0.5.18-alpha