robotindex Bitcraze Crazyflie 2.1+
An open-source nano quadcopter from Bitcraze that weighs about 29 g and fits in the palm of a hand. It is built for development, research, education and swarming: a dual-MCU board, an expansion port for add-on decks, wireless firmware updates, and a radio that reaches beyond 1 km line of sight with the Crazyradio PA. The Crazyflie 2.1+ (2024) replaced the Crazyflie 2.1 (2019) with a better battery and propellers, and costs $240.
Manufacturer page — store.bitcraze.io →
Image: Bitcraze (Crazyflie, shown with propeller guards and an expansion deck)
Specs
Price
$240Crazyflie 2.1+, Bitcraze store
Takeoff Weight
29 gControl board with battery
Size
92 × 92 × 29 mmMotor to motor
Payload
15 gCrazyflie 2.1 datasheet
Flight Time
~7 minStock battery; Crazyflie 2.1 datasheet
Charge Time
40 minMicro-USB, on-board charger
Main MCU
STM32F405Cortex-M4, 168 MHz; 1 MB flash
Radio MCU
nRF51822Radio and power management
Sensors
BMI088 + BMP388IMU and pressure sensor
Radio
2.4 GHz + BLE1 km+ LOS with Crazyradio PA
Expansion
Deck portAutomatic deck detection
Released
2024Crazyflie 2.1 launched 2019
Reference Price
The Crazyflie 2.1+ costs $240 at Bitcraze's store and includes the control board, a 250 mAh LiPo battery, five motors (one spare), ten propellers (six spare), motor mounts, a battery holder deck and a micro-USB cable. The original Crazyflie 2.1 was $225; Bitcraze lists it as discontinued and replaced by the 2.1+. The Crazyradio PA dongle, expansion decks and any controller are sold separately. robotindex does not sell this product.
Insights
The Crazyflie is the standard small research drone: it is light enough to fly indoors around people and cheap enough to fly in swarms. The Crazyflie 2.1 arrived in 2019 and the 2.1+ in 2024, with an upgraded battery and propellers that Bitcraze says improve flight performance by up to 15%. The line has since gained the Crazyflie 2.1 Brushless (2025) and the Crazyflie Bolt board for larger builds; all share the expansion-deck system. The firmware is open source under LGPL-3.0, with development tools, APIs in several languages and hardware schematics published by Bitcraze, which is why this page carries the Open Source badge; the hardware licence itself was not confirmed. The base kit has no propeller guards, camera or controller: the photo shows a unit with third-party guards and an add-on deck.
Verified against Bitcraze's store pages for the Crazyflie 2.1 and 2.1+ (store.bitcraze.io), its Crazyflie 2.1 product page and datasheet (bitcraze.io), the platform overview, and the crazyflie-firmware repository on GitHub, as of October 2026. Flagged as uncertain: the 7-minute flight time, 15 g payload and charge time are from the Crazyflie 2.1 datasheet, and Bitcraze publishes no separate figures for the 2.1+; weight is 29 g on the datasheet but 27 g on the store description; the $240 price is the store listing in USD; the hardware licence was not confirmed, only Bitcraze's statement that schematics are available; the page is titled for the 2.1+ because the 2.1 is discontinued, though it was requested as the 2.1; and the photo is a low-resolution third-party image showing a Crazyflie with propeller guards and an expansion deck.