FastLED - The Universal LED Library

Transform any microcontroller into an LED powerhouse.

Drive 30,000+ LEDs on high-end devices • Sub-$1 compatibility on tiny chips • Background rendering for responsive apps • Nearly every LED chipset supported • **#2 most popular Arduino library**

📊 Detailed Build Status (Click to expand all platform badges)

The build system is undergoing optimization and some builds may appear red during migration. Despite any red status, everything still works.

Arduino Family

Core Boards:

ARM Boards: *

ATtiny Series: **

*Notes: * Giga-R1 support added in 3.9.14 • ** ATtiny4313 has limited memory (WS2812 Blink + APA102 examples only)

Teensy Series

Standard Models:

Special Features:

NRF52 (Nordic)

*Note: NRF52 XiaoBLE board has mbed engine but doesn't compile against Arduino.h for unknown reasons.

Apollo3 (Ambiq)

*Beta support added in 3.10.2

STM32 (STMicroelectronics)

*Note: STM103TB has limited PlatformIO support

Raspberry Pi Pico

ESP32 (Espressif)

ESP8266:

ESP32 Classic:

ESP32 S-Series:

ESP32 C-Series: *

ESP32 Advanced:

Special Features:

Legacy:

*Notes: * ESP32-C2 support added in 3.9.10 • Espressif compatibility evaluation

Specialty Platforms

x86:

WebAssembly:

Library Size Validation

Core Platforms:

Teensy Platforms:

⚡ Get Blinking in 30 Seconds

#include <FastLED.h>
#define NUM_LEDS 60
CRGB leds[NUM_LEDS];
 
void setup() { 
  FastLED.addLeds<WS2812, 6>(leds, NUM_LEDS); 
}
 
void loop() {
  leds[0] = CRGB::Red; FastLED.show(); delay(500);
  leds[0] = CRGB::Blue; FastLED.show(); delay(500);
}

✅ Works on Arduino, ESP32, Teensy, Raspberry Pi, and 50+ other platforms

🚀 Why FastLED?

Massive Scale	Tiny Footprint	Background Rendering	Universal
Drive 30,000 LEDs on Teensy 4.1	Runs on $0.50 ATtiny chips	ESP32/Teensy render while you code	Works on 50+ platforms
50 parallel strips on Teensy	<2KB on Arduino Uno	Never miss user input	Nearly every LED chipset

🎯 Performance: Zero-cost global brightness • High-performance 8-bit math, memory efficient on platforms that need it. 🔧 Developer Experience: Quick platform switching • Extensive examples • Active community support

Table of Contents

• 🆕 Latest Feature
• ⭐ Community Growth
• 🆕 Latest Features
• 🌍 Platform Support
• 📦 Installation
• 📚 Documentation & Support
• 🎮 Advanced Features
• 🤝 Contributing

⭐ Community Growth

🆕 Latest Features

FastLED 3.10.0: Animartrix Out of Beta

Advanced animation framework for complex LED visualizations and effects.

FastLED 3.9.16: WaveFx / Multi Layer Compositing

Multi-layer compositing & time-based animation control for tech-artists.

https://github.com/user-attachments/assets/ff8e0432-3e0d-47cc-a444-82ce27f562af

3.9.13	3.9.10	3.9.8	3.9.2
**HD107 Turbo** 40MHz LED support	**ESP32 SPI** Super stable WS2812 driver	**Massive Teensy** 50 parallel pins on 4.1	**WS2812 Overclock** Up to 70% speed boost

3.7.7	More Features
**RGBW Support** White channel LED strips	📋 Full Changelog 📺 Demo Videos

📺 Live Demos • 📋 Full Changelog

📖 Detailed Feature Information (Click to expand)

New in 3.10.0: Animartrix out of beta

New in 3.9.16: WaveFx / Multi Layer Compositing / Time-based animation control

Video:

https://github.com/user-attachments/assets/ff8e0432-3e0d-47cc-a444-82ce27f562af

Major release for tech-artists!

Lots of improvements in this release, read the full change list here

Links

• This demo -> FxWave2d
  • Wave Simulation Library
• FireCylinder
  • Wraps around so that (0,y) ~= (width-1,y)
• TimeAlpha
  • Precision control of animations with time-based alpha transition.

New in 3.9.13: HD107 "Turbo" 40Mhz LED Support

New in 3.9.12: WS2816 "HD" LED support

New in 3.9.10: Super Stable WS2812 SPI driver for ESP32

New in 3.9.9: 16-way Yves I2S parallel driver for the ESP32-S3

*Note some users find that newer versions of the ESP32 Arduino core (3.10) don't work very well, but older versions do, see issue 1903

New in 3.9.8 - Massive Teensy 4.1 & 4.0 WS2812 LED output

• Teensy 4.1: 50 parallel pins
• Teensy 4.0: 42 parallel pins

New in 3.9.2 - Overclocking of WS2812

Update: max overclock has been reported at +70%: https://www.reddit.com/r/FastLED/comments/1gkcb6m/fastled_FASTLED_OVERCLOCK_17/

New in 3.7.7 - RGBW LED Strip Support

🌍 Platform Support

Platform Categories

Arduino Family	ESP32 Series	Teensy	ARM	Specialty
Uno, Nano, Mega Due, Giga R1, R4	ESP32, S2, S3, C3 C6, H2, P4	3.0, 3.1, 4.0, 4.1 LC + OctoWS2811	STM32, NRF52 Apollo3	Raspberry Pi WASM, x86

FastLED supports 50+ platforms! From sub-$1 ATtiny chips to high-end Teensy 4.1 with 50 parallel outputs.

📦 Installation

Quick Install Options

Arduino IDE	PlatformIO	Package Managers
Library Manager → Search "FastLED" → Install	lib_deps = fastled/FastLED	pio pkg install --library "fastled/FastLED"
Or install latest release .zip	Add to platformio.ini	Command line installation

Template Projects

• 🎯 Arduino + PlatformIO Starter - Best of both worlds, works with both IDEs
• 🚀 [FastLED Examples](examples) - 100+ ready-to-run demos
  
• 🌐 Web Compiler - Test in your browser

Arduino IDE Setup Instructions (Click to expand)

After installing the Arduino IDE, add FastLED through the Library Manager:

📚 Documentation & Support

📖 Documentation	💬 Community	🐛 Issues	📺 Examples
API Reference	Reddit r/FastLED	GitHub Issues	Live Demos
Doxygen Docs	1000s of users & solutions	Bug reports & feature requests	[GitHub Examples](examples)

Need Help? Visit r/FastLED - thousands of knowledgeable users and extensive solution history!

🎮 Advanced Features

Performance Leaders: Parallel Output Records

Platform	Max Parallel Outputs	Performance Notes
Teensy 4.1	50 parallel strips	Current record holder - Example
Teensy 4.0	42 parallel strips	High-performance ARM Cortex-M7
ESP32DEV	24 via I2S + 8 via RMT	I2S Example
ESP32-S3	16 via I2S + 4 via RMT	S3 Example

Note: Some ESP32 Arduino core versions (3.10+) have compatibility issues. Older versions work better - see issue #1903

Exotic Setups (120+ Outputs!)

Custom shift register boards can achieve extreme parallel output:

• ESP32DEV: 120-output virtual driver
• ESP32-S3: 120-output S3 driver

Supported LED Chipsets

FastLED supports virtually every LED chipset available:

Clockless (3-wire)	SPI-based (4-wire)	Specialty
WS281x Family: WS2811, WS2812 (NeoPixel), WS2812-V5B, WS2815	APA102 / DotStars: Including HD107s (40MHz turbo)	SmartMatrix Panels
TM180x Series: TM1809/4, TM1803	High-Speed SPI: LPD8806, WS2801, SM16716	DMX Output
Other 3-wire: UCS1903, GW6205, SM16824E	APA102HD: Driver-level gamma correction	P9813 Total Control

RGBW Support: WS2816 and other white-channel LED strips • Overclocking: WS2812 up to 70% speed boost

More details: Chipset Reference Wiki

APA102 High Definition Mode

#define LED_TYPE APA102HD  // Enables hardware gamma correction
void setup() {
  FastLED.addLeds<LED_TYPE, DATA_PIN, CLOCK_PIN, RGB>(leds, NUM_LEDS);
}

Read more: APA102 HD Documentation • Rust Implementation

🛠️ Development & Contributing

Ready to contribute? FastLED welcomes code contributions, platform testing, documentation improvements, and community support.

🔧 Development Setup & Contributing Guide (Click to expand)

Quick Development Setup

Zero pain setup - can be done from command line in seconds with uv or python:

Steps:

1. Fork the repository on GitHub
2. Clone your fork locally: git clone https://github.com/yourusername/FastLED.git
   
3. Test compilation: bash compile (select your target platform)
4. Make your changes and test
5. Push to your fork and create a pull request

See our detailed Contributing Guide for more information.

Testing Other Devices

Use the compile script to test on 20+ platforms:

• Teensy series, ESP32 variants, Arduino family, ARM boards, and more
• Automated testing ensures compatibility across all supported platforms

How to Help

📋 How to Help	🔗 Resources
Code contributions: Bug fixes, new features, optimizations	Contributing Guide
Platform support: Help test on new/existing platforms	[Platform Testing](compile)
Documentation: Improve examples, fix typos, add tutorials	Documentation
Community: Answer questions on Reddit, report issues	r/FastLED

Platform Porting: Information on porting FastLED to new platforms: PORTING.md

About FastLED

What's in the name? Originally "FastSPI_LED" focused on high-speed SPI, but evolved to support all LED types and became "FastLED" - everything fast, for LEDs.

Official Site: fastled.io - documentation, issues, and news

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Daniel Garcia, Founder of FastLED

In Memory of Daniel Garcia Daniel Garcia, the brilliant founder of FastLED, tragically passed away in September 2019 in the Conception dive boat fire alongside his partner, Yulia. This heartbreaking loss was felt deeply by the maker and developer community, where Daniel's contributions had left an indelible mark.

Daniel was more than just a talented programmer; he was a passionate innovator who transformed the way creators interacted with LED technology. His work on FastLED brought high-performance LED control to countless projects, empowering developers to craft breathtaking installations.

In his personal life, Daniel was known for his kindness and creativity. His pride in FastLED and the vibrant community it fostered was a testament to his dedication to open-source development and his commitment to helping others bring light into the world.

While Daniel is no longer with us, his legacy continues through the FastLED library and the countless makers who use it. The community he built serves as a living tribute to his ingenuity, generosity, and the joy he found in sharing his work with the world.

About the Current Contributor

Zach Vorhies, the current main contributor to FastLED, briefly worked with Dan in 2014 in San Francisco and was an avid user of the FastLED library for over 13 years. After Daniel Garcia’s untimely passing, Zach stepped up to ensure FastLED’s continued growth and development.

Zach has this to say about FastLED:

"The true power of FastLED lies in its ability to transform programmers into LED artists. Free space becomes their canvas; bending light is their medium. FastLED is a collective effort by programmers who want to manifest the world that science fiction writers promised us. -- To contribute code to FastLED is to leave behind a piece of something immortal."

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💫 In memory of Daniel Garcia and the vision that transforms programmers into LED artists

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