# Optiboot/optiboot

Small and Fast Bootloader for Arduino and other Atmel AVR chips

Repository: https://github.com/Optiboot/optiboot
Canonical: https://ross.abutalabs.com/products/optiboot
Language: C++
License: NOASSERTION
License Family: other
Last push: 2026-02-15T07:05:47+00:00

## Health v2 (maintenance only)
Score: 53/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 67, release rhythm 8, longevity 100
- inputs: {"age_days": 4190, "days_push": 199, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1176, forks 413 (observed 2026-08-28T04:03:52.580087+00:00)

## What it is
Optiboot is a small (512-byte) and fast bootloader for Arduino boards and Atmel/Microchip AVR microcontrollers, replacing the stock Arduino bootloader to free flash space and speed up sketch uploads. It supports a wide range of AVR chips from 8-pin ATtinys to the ATmega2560, plus newer Mega-0/Tiny-0/Tiny-1 series via optiboot_x.

## Use cases
- free up extra flash space for larger Arduino sketches
- make sketch uploads to Arduino boards faster
- replace the stock bootloader on ATmega328p, ATmega168, or ATmega8 boards
- add bootloader support to non-Arduino AVR chips
- bootload ATtiny and ATmega USB-family chips like ATmega32u4
- customize bootloader baud rate, CPU frequency, or serial port

## When to choose
- you need more program space or faster uploads on classic AVR Arduino boards
- you are building custom AVR hardware and need a bootloader
- you maintain an Arduino core and want to bundle Optiboot

## When to avoid
- you just want to update an existing Optiboot install - use your board's Arduino core instead
- you target non-AVR boards like ESP32, SAMD, or RP2040
- you need OTA or advanced bootloader features

## Facets
- artifact type: application
- maturity: active
- function: embedded, developer-tools
- domain: embedded-systems, hardware, developer-tools
- platform: embedded, cross-platform
- tags: bootloader, arduino, avr, microcontroller, firmware

## Member repositories
- Optiboot/optiboot (main) score 53

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:52.580087+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:26:33.695831+00:00, confidence not recorded.
  - readme: https://github.com/Optiboot/optiboot (fetched 2026-08-28T04:03:52.580087+00:00, sha d7d8c5c53eaa)
- Data as of 2026-08-30T08:39:29.467469+00:00.