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The Teensy 4.0 is a compact USB development board built around a 600 MHz ARM Cortex-M7 microcontroller. It offers unusually high processing capability for its size, with hardware floating point, DSP instructions, DMA, audio interfaces and extensive peripheral support. PJRC announced its availability in 2019, so “new” describes the board’s impact when launched—not a 2026 release. Choose it when board size matters and its 3.3 V-only I/O and available pins fit your design; choose the larger Teensy 4.1 when you need substantially more accessible I/O, flash, Ethernet or built-in microSD storage.
What is the Teensy 4.0?
Teensy 4.0 is a development board for prototyping, experimentation and learning. Its central processor is from NXP’s i.MX RT1062 family and runs a 600 MHz ARM Cortex-M7 core. That rating is a published specification, not an application benchmark: real performance depends on code, peripherals, memory access and software.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
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Teensy 4.0 (Headers) | $26.80 | Buy on Amazon |
| 2 |
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Teensy 4.0 (Without Pins) | $23.80 | Buy on Amazon |
| 3 |
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Teensy 4.0 iMXRT1062 Microcontroller Development Board (Lockable Version) | $23.80 | Buy on Amazon |
| 4 |
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Teensy 4.0 iMXRT1062 Microcontroller Development Board (Standard Non-Lockable Version) | $23.80 | Buy on Amazon |
| 5 |
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Teensy 4.1 (with Pins) | $43.08 | Buy on Amazon |
The architecture includes hardware floating-point support for 32-bit and 64-bit calculations, DSP instructions, a 32-channel general-purpose DMA controller and two 32 KiB caches. Those features are useful for control systems, signal processing, audio, displays and other workloads that would be difficult on a slower 8-bit or basic 32-bit board.
PJRC’s official launch announcement said the board was available in 2019. Current documentation describes the supported hardware, but does not establish a newly released model in 2026.
#1 Best Overall
- Features am ARM Cortex-M7 processor at 600MHz with a NXP iMXRT1062 chip: a true real-time microcontroller platform
- Dual-issue superscaler processor: Can execute two instructions per clock cycle
- Tightly Coupled Memory: allows fast single cycle access to memory using a pair of 64 bit wide buses
- Provides a power shut-off feature: By connecting a pushbutton to the On/Off pin, the 3.3V power supply can be completely disabled by holding the button for 5 seconds, & turned back on by a brief button press
- The same size and shape as Teensy 3.2: Retains compatibility with most of the pin functions. Pre soldered header pins
Teensy 4.0 specifications that matter
| Specification | Teensy 4.0 | What it means in practice |
|---|---|---|
| Processor | 600 MHz ARM Cortex-M7, NXP i.MX RT1062 family | High MCU-class processing capacity; no universal application-speed guarantee |
| RAM | 1,024 KiB | Supports larger buffers and more complex firmware than many entry-level boards |
| Flash | 2,048 KiB listed; 64 KiB reserved for recovery and EEPROM emulation | Do not treat the entire listed flash amount as available to user code |
| Digital I/O | 40 total; 24 readily accessible on board edges for solderless breadboard use | Additional pads are on the underside, so physical access matters |
| Analog inputs | 14 | Useful for sensor and control interfaces |
| PWM outputs | 31 | Supports motor, lighting and other duty-cycle control designs |
| Serial interfaces | Seven serial ports | Allows multiple serial peripherals, subject to pin assignments and software support |
| Other interfaces | Three SPI, three I2C, two I2S/TDM audio, one S/PDIF, three CAN buses including one CAN FD | Strong fit for connected sensors, instruments and audio projects |
| USB | USB device and host capability | Can connect to a computer or, with suitable hardware and software, act as a USB host |
How fast is a Teensy 4.0?
The processor is specified at 600 MHz, making the Teensy 4.0 exceptionally fast among microcontroller development boards of its physical size. Hardware floating point and DSP instructions can reduce the work required for mathematical and signal-processing operations, while DMA can move data without making the CPU handle every transfer.
That specification does not predict a fixed frame rate, audio-polyphony limit or control-loop frequency. Those outcomes depend on the algorithm, compiler settings, memory layout, connected devices and libraries. Treat 600 MHz as the processor clock rating, and test the complete workload when timing is critical.
Rank #2
- 1024K RAM (512K of Tightly Coupled Memory)
- 2048K Flash (64K Reserved for Recovery & EEPROM Emulation)
- 2 USB Ports (Both 480 MBit/Sec)
- 3 CAN Bus (1 with CAN FD), 2 I2S Digital Audio
Graphics and pixel processing
PJRC describes a Pixel Processing Pipeline capable of color-space conversion, blending, chroma keying and resizing. The product documentation qualifies software support for this feature as experimental, so confirm library and component support before making it central to a product design.
Electrical and mechanical constraints
3.3 V logic is a hard requirement
Teensy 4.0 digital pins use 0–3.3 V logic and are not 5 V tolerant. A 5 V sensor, module or controller should not be connected directly unless its electrical interface is designed for that voltage. Use an appropriate level shifter or other protection and check the electrical specifications for the exact pin and peripheral.
Rank #3
- HIGH-PERFORMANCE MICROCONTROLLER: Features an ARM Cortex-M7 processor at 600MHz (can be overclocked), with a NXP iMXRT1062 chip, the most powerful microcontroller available today
- ARDUINO-COMPATIBLE: The Teensy is compatible with the Arduino IDE programming environment as well as many of the existing Arduino libraries, so it is easy to get programmed and running
- RAM: 1024K RAM (512K is tightly coupled); 2048K Flash (64K reserved for recovery & EEPROM emulation)
- MULTIPLE I/O: 2 USB ports, both 480 MBit/sec; 3 CAN Bus (1 with CAN FD); 31 PWM pins; 40 digital pins, all interrupt capable; 14 analog pins, 2 ADCs on chip; 2 I2S Digital Audio
- LOCKABLE PROGRAM CODE OPTION: The LOCKABLE version of the Teensy 4.0 is suitable for commercial products and secure applications to protect your program code from unauthorized access and copying. When code security is not required, we recommend the STANDARD NON-LOCKABLE version.
Not every pin is convenient on a breadboard
The board has 40 I/O signals, but PJRC identifies 24 as readily accessible on the board edges for solderless-breadboard use. Other signals are available on underside pads. A project that needs many simultaneous connections may therefore require a custom carrier board, soldered wiring or a larger Teensy.
Headers and cable may be separate
PJRC recommends a USB cable and two 14×1 pin strips as accessories. Check whether the particular board listing has headers installed: a standard board and a pin-soldered version are different offerings, and that choice affects how quickly it can be plugged into a breadboard.
Rank #4
- HIGH-PERFORMANCE MICROCONTROLLER: Features an ARM Cortex-M7 processor at 600MHz (can be overclocked), with a NXP iMXRT1062 chip, the most powerful microcontroller available today
- ARDUINO-COMPATIBLE: The Teensy is compatible with the Arduino IDE programming environment as well as many of the existing Arduino libraries, so it is easy to get programmed and running
- RAM: 1024K RAM (512K is tightly coupled); 2048K Flash (64K reserved for recovery & EEPROM emulation)
- MULTIPLE I/O: 2 USB ports, both 480 MBit/sec; 3 CAN Bus (1 with CAN FD); 31 PWM pins; 40 digital pins, all interrupt capable; 14 analog pins, 2 ADCs on chip; 2 I2S Digital Audio
- LOCKABLE PROGRAM CODE OPTION: The LOCKABLE version of the Teensy 4.0 is suitable for commercial products and secure applications to protect your program code from unauthorized access and copying. When code security is not required, we recommend the STANDARD NON-LOCKABLE version.
Hardware revisions
PJRC notes that the processor revision changed after December 2021, followed by component substitutions in March, June and August 2022. The later processor revision fixed obscure CAN and USB isochronous-mode bugs. Do not infer the revision in a particular unit without its manufacturing details.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Fix the driver behind crashes, sound loss and screen glitches3Clear out junk files and repair common Windows errorsTeensy 4.0 vs. Teensy 4.1
Teensy 4.1 is not simply a faster version of 4.0. Both use the same 600 MHz-class Cortex-M7 family, while 4.1 mainly expands I/O, storage and connectivity. Compare the interfaces your project needs and the space available for mounting.
Best Value
- Pre-Soldered Header Pins
- ARM Cortex-M7 at 600 MHz
- 4X Larger Flash Memory
- Provides Greater I/O Capability
- Includes Ethernet PHY, SD Card Socket, and USB Host Port
| Feature | Teensy 4.0 | Teensy 4.1 |
|---|---|---|
| Total I/O | 40 | 55 |
| Analog inputs | 14 | 18 |
| PWM outputs | 31 | 35 |
| Serial ports | 7 | 8 |
| Flash | 2 MiB listed, with 64 KiB reserved | 8 MiB |
| Ethernet | No built-in Ethernet PHY | Built-in Ethernet PHY |
| microSD | No built-in socket | Built-in microSD socket |
Choose Teensy 4.0 when
- Your enclosure or mounting pattern benefits from the smaller board.
- You can work within 40 total signals and 14 analog inputs, including the 24 edge-accessible breadboard pins.
- External storage and networking hardware are acceptable or unnecessary.
- Your peripherals support 3.3 V logic, or you have a proper level-shifting design.
Choose Teensy 4.1 when
- You need more pins, analog channels or a further serial port.
- Your firmware or assets need substantially more flash.
- Built-in Ethernet or a microSD socket simplifies the design.
- The larger board is easier to mount than adding a carrier board or external expansion to a 4.0.
Software and peripheral ecosystem
Teensy supports libraries and examples for audio, displays, LEDs and many other peripherals. Compatibility and performance still depend on the exact component, library and software version. Verify pin assignments, voltage requirements, timing and memory use for every module rather than assuming that a library-supported category guarantees support for a particular product.
Quick Recap
A practical selection checklist
- List every required interface: digital, analog, PWM, serial, SPI, I2C, audio, CAN, USB, Ethernet and storage.
- Count signals that must be physically reachable on a breadboard or connector; do not count underside pads as equally convenient.
- Confirm that every connected device accepts 3.3 V logic, or budget for level shifting and protection.
- Estimate firmware, audio and graphics storage while excluding the 64 KiB reserved portion of the 4.0’s listed flash.
- Check library support and pin conflicts for the exact peripherals and software versions.
- Include the USB cable, header strips, carrier board, level shifters and other interface hardware in the build plan.
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