LLM inference in C/C++
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Reese Levine 15bff84bf5
ggml webgpu: initial flashattention implementation (#18610)
* FlashAttention (#13)

* Add inplace softmax

* Move rms_norm to split row approach

* Update debug for supports_op

* clean up debug statements

* neg f16xf32xip builds and runs, havent actually ran a model that uses neg kernel yet though

* neg passes backend test

* unary operators pass ggml tests

* rms_norm double declaration bug atoned

* abides by editor-config

* removed vestigial files

* fixed autoconfig

* All operators (inlcluding xielu) working

* removed unnecesarry checking if node->src[1] exists for unary operators

* responded and dealt with PR comments

* implemented REPL_Template support and removed bug in unary operators kernel

* formatted embed wgsl and ggml-webgpu.cpp

* Faster tensors (#8)

Add fast matrix and matrix/vector multiplication.

* Use map for shader replacements instead of pair of strings

* Wasm (#9)

* webgpu : fix build on emscripten

* more debugging stuff

* test-backend-ops: force single thread on wasm

* fix single-thread case for init_tensor_uniform

* use jspi

* add pthread

* test: remember to set n_thread for cpu backend

* Add buffer label and enable dawn-specific toggles to turn off some checks

* Intermediate state

* Fast working f16/f32 vec4

* Working float fast mul mat

* Clean up naming of mul_mat to match logical model, start work on q mul_mat

* Setup for subgroup matrix mat mul

* Basic working subgroup matrix

* Working subgroup matrix tiling

* Handle weirder sg matrix sizes (but still % sg matrix size)

* Working start to gemv

* working f16 accumulation with shared memory staging

* Print out available subgroup matrix configurations

* Vectorize dst stores for sg matrix shader

* Gemv working scalar

* Minor set_rows optimization (#4)

* updated optimization, fixed errors

* non vectorized version now dispatches one thread per element

* Simplify

* Change logic for set_rows pipelines

---------

Co-authored-by: Neha Abbas <nehaabbas@macbookpro.lan>
Co-authored-by: Neha Abbas <nehaabbas@ReeseLevines-MacBook-Pro.local>
Co-authored-by: Reese Levine <reeselevine1@gmail.com>

* Comment on dawn toggles

* Working subgroup matrix code for (semi)generic sizes

* Remove some comments

* Cleanup code

* Update dawn version and move to portable subgroup size

* Try to fix new dawn release

* Update subgroup size comment

* Only check for subgroup matrix configs if they are supported

* Add toggles for subgroup matrix/f16 support on nvidia+vulkan

* Make row/col naming consistent

* Refactor shared memory loading

* Move sg matrix stores to correct file

* Working q4_0

* Formatting

* Work with emscripten builds

* Fix test-backend-ops emscripten for f16/quantized types

* Use emscripten memory64 to support get_memory

* Add build flags and try ci

---------

Co-authored-by: Xuan Son Nguyen <son@huggingface.co>

* Remove extra whitespace

* Move wasm single-thread logic out of test-backend-ops for cpu backend

* Disable multiple threads for emscripten single-thread builds in ggml_graph_plan

* Refactored pipelines and workgroup calculations (#10)

* refactored pipelines

* refactored workgroup calculation

* removed commented out block of prior maps

* Clean up ceiling division pattern

---------

Co-authored-by: Neha Abbas <nehaabbas@eduroam-169-233-141-223.ucsc.edu>
Co-authored-by: Reese Levine <reeselevine1@gmail.com>

* Start work on flash attention

* Shader structure set up (many bugs still)

* debugging

* Working first test

* Working with head grouping, head sizes to 128, logit softcap, mask/sinks enabled, f32

* Generalize softmax to work with multiple subgroups, f16 accumulation, mask shared memory tiling

* Start work on integrating pre-wgsl

* Separate structs/initial shader compilation library into separate files

* Work on compilation choices for flashattention

* Work on subgroup matrix/tile size portability

* subgroup size agnostic online softmax

* Cleanups, quantization types

* more cleanup

* fix wasm build

* Refactor flashattention to increase parallelism, use direct loads for KV in somce cases

* Checkpoint

* formatting

* Update to account for default kv cache padding

* formatting shader

* Add workflow for ggml-ci webgpu

* Try passing absolute path to dawn in ggml-ci

* Avoid error on device destruction, add todos for proper cleanup

* Fix unused warning

* Forgot one parameter unused

* Move some flashattn computation to f32 for correctness
2026-01-08 08:23:39 -08:00
.devops fix(docker): add missing libglvnd libraries to Vulkan image (#18664) 2026-01-07 16:57:42 +01:00
.gemini contributing: tighten AI usage policy (#18388) 2025-12-29 16:01:32 +01:00
.github ggml webgpu: initial flashattention implementation (#18610) 2026-01-08 08:23:39 -08:00
benches/dgx-spark benches : add eval results (#17139) 2025-11-10 10:44:10 +02:00
ci ggml webgpu: initial flashattention implementation (#18610) 2026-01-08 08:23:39 -08:00
cmake cmake : simplify build info detection using standard variables (#17423) 2025-12-04 12:42:13 +02:00
common vendor : update cpp-httplib to 0.30.0 (#18660) 2026-01-08 13:53:54 +01:00
docs ggml webgpu: add CEIL operation support (#18605) 2026-01-05 11:38:57 -08:00
examples model-conversion : add warn about transformers mismatch (#18691) 2026-01-08 09:29:53 +01:00
ggml ggml webgpu: initial flashattention implementation (#18610) 2026-01-08 08:23:39 -08:00
gguf-py gguf-py : add requests to dependencies (#18629) 2026-01-06 08:56:38 +01:00
grammars docs : document that JSON Schema is not available to model when using response_format (#18492) 2025-12-30 15:13:49 -06:00
include llama-fit-params: free memory target per device (#18679) 2026-01-08 10:07:58 +01:00
licenses tools : remove llama-run (#18661) 2026-01-07 16:18:26 +01:00
media media : add transparent icon svg and png [no ci] (#15891) 2025-09-10 14:51:28 +03:00
models common : default content to an empty string (#18485) 2025-12-30 12:00:57 -06:00
pocs ggml : move AMX to the CPU backend (#10570) 2024-11-29 21:54:58 +01:00
requirements convert : update transformers requirements (#16866) 2025-10-30 23:15:03 +01:00
scripts vendor : update cpp-httplib to 0.30.0 (#18660) 2026-01-08 13:53:54 +01:00
src llama-fit-params: free memory target per device (#18679) 2026-01-08 10:07:58 +01:00
tests vendor : update cpp-httplib to 0.30.0 (#18660) 2026-01-08 13:53:54 +01:00
tools vendor : update cpp-httplib to 0.30.0 (#18660) 2026-01-08 13:53:54 +01:00
vendor vendor : update cpp-httplib to 0.30.0 (#18660) 2026-01-08 13:53:54 +01:00
.clang-format fix: apply clang-format to CUDA macros (#16017) 2025-09-16 08:59:19 +02:00
.clang-tidy clang-tidy : disable warning about performance enum size (#16127) 2025-09-22 19:57:46 +02:00
.dockerignore ci : fix docker build number and tag name (#9638) 2024-09-25 17:26:01 +02:00
.ecrc common : Update stb_image.h to latest version (#9161) 2024-08-27 08:58:50 +03:00
.editorconfig editorconfig : ignore benches/ (#17140) 2025-11-10 12:17:19 +02:00
.flake8 llama : move end-user examples to tools directory (#13249) 2025-05-02 20:27:13 +02:00
.gitignore scripts : add pr2wt.sh (#18644) 2026-01-07 15:16:20 +02:00
.gitmodules ggml : remove kompute backend (#14501) 2025-07-03 07:48:32 +03:00
.pre-commit-config.yaml convert.py : add python logging instead of print() (#6511) 2024-05-03 22:36:41 +03:00
AGENTS.md contributing: tighten AI usage policy (#18388) 2025-12-29 16:01:32 +01:00
AUTHORS authors : update (#12271) 2025-03-08 18:26:00 +02:00
CLAUDE.md contributing: tighten AI usage policy (#18388) 2025-12-29 16:01:32 +01:00
CMakeLists.txt build : move _WIN32_WINNT definition to headers (#17736) 2025-12-04 07:04:02 +01:00
CMakePresets.json cmake : Add CMake presets for Linux and GCC (#14656) 2025-07-13 08:12:36 +03:00
CODEOWNERS llama.android : Rewrite Android binding (w/o cpu_features dep) (#17413) 2025-12-17 10:14:47 +02:00
CONTRIBUTING.md contributing: tighten AI usage policy (#18388) 2025-12-29 16:01:32 +01:00
LICENSE license : update copyright notice + add AUTHORS (#6405) 2024-04-09 09:23:19 +03:00
Makefile make : remove make in favor of CMake (#15449) 2025-08-20 13:31:16 +03:00
README.md tools : remove llama-run (#18661) 2026-01-07 16:18:26 +01:00
SECURITY.md security : add collaborator guidance (#18081) 2025-12-16 11:17:11 +02:00
build-xcframework.sh cmake : move OpenSSL linking to vendor/cpp-httplib (#17177) 2025-11-12 12:32:50 +01:00
convert_hf_to_gguf.py convert : more variants of rope_theta config entries (#18668) 2026-01-07 22:34:51 +01:00
convert_hf_to_gguf_update.py model: support youtu-vl model (#18479) 2026-01-01 19:25:54 +01:00
convert_llama_ggml_to_gguf.py py : fix wrong input type for raw_dtype in ggml to gguf scripts (#8928) 2024-08-16 13:36:30 +03:00
convert_lora_to_gguf.py convert : allow quantizing lora again (#17453) 2025-11-24 15:50:55 +01:00
flake.lock flake.lock: Update (#10470) 2024-11-24 08:03:25 -08:00
flake.nix fix(nix): remove non-functional llama-cpp cachix cache from flake.nix (#15295) 2025-08-13 11:21:31 -07:00
mypy.ini convert : partially revert PR #4818 (#5041) 2024-01-20 18:14:18 -05:00
poetry.lock build(python): Package scripts with pip-0517 compliance 2024-07-04 15:39:13 +00:00
pyproject.toml gguf-py : avoid requiring pyside6 for other scripts (#13036) 2025-05-05 22:27:31 -04:00
pyrightconfig.json model-conversion : use CONVERTED_MODEL value for converted model [no ci] (#17984) 2025-12-13 08:34:26 +01:00
requirements.txt `tool-call`: fix Qwen 2.5 Coder support, add micro benchmarks, support trigger patterns for lazy grammars (#12034) 2025-03-05 13:05:13 +00:00

README.md

llama.cpp

llama

License: MIT Release Server

Manifesto / ggml / ops

LLM inference in C/C++

Recent API changes

Hot topics


Quick start

Getting started with llama.cpp is straightforward. Here are several ways to install it on your machine:

Once installed, you'll need a model to work with. Head to the Obtaining and quantizing models section to learn more.

Example command:

# Use a local model file
llama-cli -m my_model.gguf

# Or download and run a model directly from Hugging Face
llama-cli -hf ggml-org/gemma-3-1b-it-GGUF

# Launch OpenAI-compatible API server
llama-server -hf ggml-org/gemma-3-1b-it-GGUF

Description

The main goal of llama.cpp is to enable LLM inference with minimal setup and state-of-the-art performance on a wide range of hardware - locally and in the cloud.

  • Plain C/C++ implementation without any dependencies
  • Apple silicon is a first-class citizen - optimized via ARM NEON, Accelerate and Metal frameworks
  • AVX, AVX2, AVX512 and AMX support for x86 architectures
  • RVV, ZVFH, ZFH, ZICBOP and ZIHINTPAUSE support for RISC-V architectures
  • 1.5-bit, 2-bit, 3-bit, 4-bit, 5-bit, 6-bit, and 8-bit integer quantization for faster inference and reduced memory use
  • Custom CUDA kernels for running LLMs on NVIDIA GPUs (support for AMD GPUs via HIP and Moore Threads GPUs via MUSA)
  • Vulkan and SYCL backend support
  • CPU+GPU hybrid inference to partially accelerate models larger than the total VRAM capacity

The llama.cpp project is the main playground for developing new features for the ggml library.

Models

Typically finetunes of the base models below are supported as well.

Instructions for adding support for new models: HOWTO-add-model.md

Text-only

Multimodal

Bindings
UIs

(to have a project listed here, it should clearly state that it depends on llama.cpp)

Tools
  • akx/ggify download PyTorch models from HuggingFace Hub and convert them to GGML
  • akx/ollama-dl download models from the Ollama library to be used directly with llama.cpp
  • crashr/gppm launch llama.cpp instances utilizing NVIDIA Tesla P40 or P100 GPUs with reduced idle power consumption
  • gpustack/gguf-parser - review/check the GGUF file and estimate the memory usage
  • Styled Lines (proprietary licensed, async wrapper of inference part for game development in Unity3d with pre-built Mobile and Web platform wrappers and a model example)
  • unslothai/unsloth 🦥 exports/saves fine-tuned and trained models to GGUF (Apache-2.0)
Infrastructure
  • Paddler - Open-source LLMOps platform for hosting and scaling AI in your own infrastructure
  • GPUStack - Manage GPU clusters for running LLMs
  • llama_cpp_canister - llama.cpp as a smart contract on the Internet Computer, using WebAssembly
  • llama-swap - transparent proxy that adds automatic model switching with llama-server
  • Kalavai - Crowdsource end to end LLM deployment at any scale
  • llmaz - ☸️ Easy, advanced inference platform for large language models on Kubernetes.
Games
  • Lucy's Labyrinth - A simple maze game where agents controlled by an AI model will try to trick you.

Supported backends

Backend Target devices
Metal Apple Silicon
BLAS All
BLIS All
SYCL Intel and Nvidia GPU
MUSA Moore Threads GPU
CUDA Nvidia GPU
HIP AMD GPU
ZenDNN AMD CPU
Vulkan GPU
CANN Ascend NPU
OpenCL Adreno GPU
IBM zDNN IBM Z & LinuxONE
WebGPU [In Progress] All
RPC All
Hexagon [In Progress] Snapdragon

Obtaining and quantizing models

The Hugging Face platform hosts a number of LLMs compatible with llama.cpp:

You can either manually download the GGUF file or directly use any llama.cpp-compatible models from Hugging Face or other model hosting sites, such as ModelScope, by using this CLI argument: -hf <user>/<model>[:quant]. For example:

llama-cli -hf ggml-org/gemma-3-1b-it-GGUF

By default, the CLI would download from Hugging Face, you can switch to other options with the environment variable MODEL_ENDPOINT. For example, you may opt to downloading model checkpoints from ModelScope or other model sharing communities by setting the environment variable, e.g. MODEL_ENDPOINT=https://www.modelscope.cn/.

After downloading a model, use the CLI tools to run it locally - see below.

llama.cpp requires the model to be stored in the GGUF file format. Models in other data formats can be converted to GGUF using the convert_*.py Python scripts in this repo.

The Hugging Face platform provides a variety of online tools for converting, quantizing and hosting models with llama.cpp:

To learn more about model quantization, read this documentation

llama-cli

A CLI tool for accessing and experimenting with most of llama.cpp's functionality.

  • Run in conversation mode

    Models with a built-in chat template will automatically activate conversation mode. If this doesn't occur, you can manually enable it by adding -cnv and specifying a suitable chat template with --chat-template NAME

    llama-cli -m model.gguf
    
    # > hi, who are you?
    # Hi there! I'm your helpful assistant! I'm an AI-powered chatbot designed to assist and provide information to users like you. I'm here to help answer your questions, provide guidance, and offer support on a wide range of topics. I'm a friendly and knowledgeable AI, and I'm always happy to help with anything you need. What's on your mind, and how can I assist you today?
    #
    # > what is 1+1?
    # Easy peasy! The answer to 1+1 is... 2!
    
  • Run in conversation mode with custom chat template
    # use the "chatml" template (use -h to see the list of supported templates)
    llama-cli -m model.gguf -cnv --chat-template chatml
    
    # use a custom template
    llama-cli -m model.gguf -cnv --in-prefix 'User: ' --reverse-prompt 'User:'
    
  • Constrain the output with a custom grammar
    llama-cli -m model.gguf -n 256 --grammar-file grammars/json.gbnf -p 'Request: schedule a call at 8pm; Command:'
    
    # {"appointmentTime": "8pm", "appointmentDetails": "schedule a a call"}
    

    The grammars/ folder contains a handful of sample grammars. To write your own, check out the GBNF Guide.

    For authoring more complex JSON grammars, check out https://grammar.intrinsiclabs.ai/

llama-server

A lightweight, OpenAI API compatible, HTTP server for serving LLMs.

  • Start a local HTTP server with default configuration on port 8080
    llama-server -m model.gguf --port 8080
    
    # Basic web UI can be accessed via browser: http://localhost:8080
    # Chat completion endpoint: http://localhost:8080/v1/chat/completions
    
  • Support multiple-users and parallel decoding
    # up to 4 concurrent requests, each with 4096 max context
    llama-server -m model.gguf -c 16384 -np 4
    
  • Enable speculative decoding
    # the draft.gguf model should be a small variant of the target model.gguf
    llama-server -m model.gguf -md draft.gguf
    
  • Serve an embedding model
    # use the /embedding endpoint
    llama-server -m model.gguf --embedding --pooling cls -ub 8192
    
  • Serve a reranking model
    # use the /reranking endpoint
    llama-server -m model.gguf --reranking
    
  • Constrain all outputs with a grammar
    # custom grammar
    llama-server -m model.gguf --grammar-file grammar.gbnf
    
    # JSON
    llama-server -m model.gguf --grammar-file grammars/json.gbnf
    

llama-perplexity

A tool for measuring the perplexity 1 (and other quality metrics) of a model over a given text.

  • Measure the perplexity over a text file
    llama-perplexity -m model.gguf -f file.txt
    
    # [1]15.2701,[2]5.4007,[3]5.3073,[4]6.2965,[5]5.8940,[6]5.6096,[7]5.7942,[8]4.9297, ...
    # Final estimate: PPL = 5.4007 +/- 0.67339
    
  • Measure KL divergence
    # TODO
    

llama-bench

Benchmark the performance of the inference for various parameters.

  • Run default benchmark
    llama-bench -m model.gguf
    
    # Output:
    # | model               |       size |     params | backend    | threads |          test |                  t/s |
    # | ------------------- | ---------: | ---------: | ---------- | ------: | ------------: | -------------------: |
    # | qwen2 1.5B Q4_0     | 885.97 MiB |     1.54 B | Metal,BLAS |      16 |         pp512 |      5765.41 ± 20.55 |
    # | qwen2 1.5B Q4_0     | 885.97 MiB |     1.54 B | Metal,BLAS |      16 |         tg128 |        197.71 ± 0.81 |
    #
    # build: 3e0ba0e60 (4229)
    

llama-simple

A minimal example for implementing apps with llama.cpp. Useful for developers.

  • Basic text completion
    llama-simple -m model.gguf
    
    # Hello my name is Kaitlyn and I am a 16 year old girl. I am a junior in high school and I am currently taking a class called "The Art of
    

Contributing

  • Contributors can open PRs
  • Collaborators will be invited based on contributions
  • Maintainers can push to branches in the llama.cpp repo and merge PRs into the master branch
  • Any help with managing issues, PRs and projects is very appreciated!
  • See good first issues for tasks suitable for first contributions
  • Read the CONTRIBUTING.md for more information
  • Make sure to read this: Inference at the edge
  • A bit of backstory for those who are interested: Changelog podcast

Other documentation

Development documentation

Seminal papers and background on the models

If your issue is with model generation quality, then please at least scan the following links and papers to understand the limitations of LLaMA models. This is especially important when choosing an appropriate model size and appreciating both the significant and subtle differences between LLaMA models and ChatGPT:

XCFramework

The XCFramework is a precompiled version of the library for iOS, visionOS, tvOS, and macOS. It can be used in Swift projects without the need to compile the library from source. For example:

// swift-tools-version: 5.10
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "MyLlamaPackage",
    targets: [
        .executableTarget(
            name: "MyLlamaPackage",
            dependencies: [
                "LlamaFramework"
            ]),
        .binaryTarget(
            name: "LlamaFramework",
            url: "https://github.com/ggml-org/llama.cpp/releases/download/b5046/llama-b5046-xcframework.zip",
            checksum: "c19be78b5f00d8d29a25da41042cb7afa094cbf6280a225abe614b03b20029ab"
        )
    ]
)

The above example is using an intermediate build b5046 of the library. This can be modified to use a different version by changing the URL and checksum.

Completions

Command-line completion is available for some environments.

Bash Completion

$ build/bin/llama-cli --completion-bash > ~/.llama-completion.bash
$ source ~/.llama-completion.bash

Optionally this can be added to your .bashrc or .bash_profile to load it automatically. For example:

$ echo "source ~/.llama-completion.bash" >> ~/.bashrc

Dependencies

  • yhirose/cpp-httplib - Single-header HTTP server, used by llama-server - MIT license
  • stb-image - Single-header image format decoder, used by multimodal subsystem - Public domain
  • nlohmann/json - Single-header JSON library, used by various tools/examples - MIT License
  • minja - Minimal Jinja parser in C++, used by various tools/examples - MIT License
  • curl - Client-side URL transfer library, used by various tools/examples - CURL License
  • miniaudio.h - Single-header audio format decoder, used by multimodal subsystem - Public domain
  • subprocess.h - Single-header process launching solution for C and C++ - Public domain