Espruino

What Espruino does

Espruino (legally Pur3 Ltd) is a Cambridge, UK-based private company founded in 2012 by Gordon Williams that develops an open-source JavaScript interpreter firmware for ARM Cortex-M microcontrollers, enabling software developers to program hardware using familiar JavaScript syntax rather than C or Arduino. The product portfolio spans eight hardware devices: the Espruino Pico and WiFi boards (STM32-based), Puck.js and Pixl.js (Bluetooth LE devices built on Nordic nRF52 chips via Raytac modules), Bangle.js and Bangle.js 2 smartwatches, Jolt.js motor driver, and the MDBT42Q module. Pricing ranges from approximately £12 for bare modules to £99.60 for Bangle.js 2, with volume discounts available. The technology stack includes a web-based IDE with REPL, syntax highlighting, Blockly graphical editing, wireless programming via Web Bluetooth, and ultra-low-power single-chip designs enabling multi-year battery life.

The company sells hardware directly through its online shop and through a global distributor network, with regional Amazon Marketplace presence. Major product launches follow a crowdfunding-first model on Kickstarter — five successful campaigns (Original, Pico, Puck.js, Bangle.js, Bangle.js 2) have validated demand and funded production. Espruino has never raised institutional venture capital; all external funding has come from crowdfunding, suggesting a bootstrapped, founder-led operating model. Customer segments are horizontal: makers and hardware hobbyists, embedded systems engineers, and smartwatch users/developers. The Bangle.js ecosystem includes a community app store with 100+ apps.

All hardware designs are CC-BY-SA licensed, all software is MPLv2 licensed, and the firmware, IDE, and documentation are fully open source on GitHub. Strategic technology partners include Nordic Semiconductor (core BLE chips), Raytac Corporation (pre-programmed modules), ST Microelectronics (Pico/WiFi processors), and Espressif Systems (ESP8266 WiFi). Headcount remains at 1-10 employees, and no revenue is publicly disclosed.

Name

Espruino

Legal name

Pur3 Ltd

Website

https://espruino.com

Company type

Private

Founded year

2012

Operating status

Operating

Headcount range

1–10 employees

Short description

Espruino (Pur3 Ltd) is a Cambridge, UK-based company that develops an open-source JavaScript interpreter for ARM Cortex-M microcontrollers, selling eight hardware boards and smartwatches priced £12-£100 to makers, embedded engineers, and smartwatch enthusiasts via direct online sales and global distributors.

Ownership category

akta.pro rank

Product category

Microcontroller Development Hardware

NAICS

Computer and Peripheral Equipment Manufacturing (3341)

SIC

Electronic Components & Accessories (3670)

akta.pro primary industry

Hardware & Embedded/IoT Programming (Microcontrollers, Raspberry Pi) (EDAMACAL)

akta.pro secondary industries

Embedded, Maker Platforms & Development Kits Retail (CRACAKAI), Game Controllers, Joysticks & Flight/Driving Sim Controls (HDACAFAC)

Keywords

• Microcontroller development boards
• JavaScript interpreter firmware
• Bluetooth Low Energy devices
• Open source hardware
• IoT prototyping platforms

Headquarters

HQ city

Cambridge

HQ country

United Kingdom

HQ region

Europe

Offices1 record

Markets served

GTM type

B2C

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Technology or R&D, Operations, Personnel, Marketing or Sales

Revenue model

1. Hardware Sales: Espruino generates revenue through direct sales of microcontroller boards and development kits. Product line includes Espruino Pico, Espruino WiFi, Puck.js, Pixl.js, Jolt.js, Bangle.js smartwatches, and MDBT42Q Bluetooth modules. The company sells directly through its online shop and through a global distributor network.
2. Accessories and Components: Sale of complementary products including replacement parts, cables, cases, straps, batteries, and third-party peripherals compatible with Espruino boards.
3. Crowdfunding Campaigns: Major products are launched and funded through Kickstarter crowdfunding campaigns before general availability, providing pre-production capital and validating market demand.

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels6 records

Core offering

Espruino designs, manufactures, and sells JavaScript-programmable microcontroller boards and Bluetooth Low Energy devices (including Pico, WiFi, Puck.js, Pixl.js, Bangle.js smartwatches, and the Jolt.js motor driver) that let software developers control hardware using familiar JavaScript instead of C/Arduino. Products are sold through the company's own online shop and a global distributor network, and are paired with a free browser-based IDE, open-source firmware (MPLv2), open hardware designs (CC-BY-SA), and a Bangle.js app ecosystem.

Product overview

Espruino is a JavaScript interpreter for microcontrollers, enabling developers to program hardware devices using JavaScript. The product portfolio includes multiple hardware boards (Bangle.js 2 smartwatch, Jolt.js BLE motor driver, Puck.js and Puck.js Lite smart buttons, Pixl.js LCD display, Espruino WiFi and Pico boards, MDBT42Q Bluetooth module) and accessories (ESP8266 WiFi module, cables, programming tools). The ecosystem includes the Espruino Web IDE, firmware, modules, tutorials, and the Bangle.js App Loader with over 100 apps. Hardware is open source (CC-BY-SA) and software is MPLv2 licensed.

Differentiator

Problem solved

Functional benefit

Products and services

• Bangle.js 2 Smart Watch Open, hackable JavaScript-programmable smartwatch with sunlight-readable always-on 1.3 inch 176x176 display, 4-week battery life, GPS, heart rate monitor, accelerometer, magnetometer, pressure sensor, water-resistant IP67, Nordic 64MHz nRF52840 ARM Cortex-M4 with Bluetooth LE; compatible with the Bangle.js App Loader.
• Jolt.js BLE Motor Driver Board Programmable Bluetooth Low Energy motor driver board based on nRF52840 SoC 64MHz ARM Cortex-M4 with 8x 1A powered outputs, 4x Qwiic connectors (12x 3.3V IO), LiPo connector with built-in charger, USB-C support, and ultra-low power consumption (0.008mA idle, 0.06mA with Bluetooth).
• Jolt.js Bundle Kit Kit including the Jolt.js board, silicone case, 300mAh LiPo battery, 4x Qwiic cables, screwdriver, and instruction card in a clear plastic box.
• Puck.js v2.1 Smart Bluetooth Button Intelligent Bluetooth button with 7x 0.1\" GPIO, MMC5603NJ magnetometer, LSM6DS3TR-C accelerometer/gyro, PCT2075TP temperature sensor, built-in light and battery sensors, RGB and IR LEDs, NFC tag, and 200mA FET output; ships with silicone cover and a CR2032 battery.
• Puck.js Lite Budget version of Puck.js without sensors, NFC, blue LED, IR transmitter, and FET; features 6x 0.1\" GPIO, red and green LEDs, and Bluetooth LE connectivity.
• Pixl.js Bluetooth LCD Display Microcontroller Bluetooth LCD display microcontroller with Arduino footprint, LCD display, Bluetooth LE, and JavaScript programmable via the Espruino interpreter.
• MDBT42Q Bluetooth Module Bare Bluetooth LE module based on Nordic nRF52832 SoC (64MHz ARM Cortex-M4) with 64kB RAM and 512kB Flash, NFC tag support, and 32 GPIO on 0.7mm pitch; used inside Puck.js and Pixl.js products.
• Espruino WiFi Board Compact 30mm x 23mm WiFi-enabled microcontroller running JavaScript on STM32F411CEU6 100MHz ARM Cortex-M4 CPU with 512KB flash, 128KB RAM, ESP8266 WiFi (802.11 b/g/n), 21 GPIO, and USB connectivity.
• Espruino Pico Tiny 33mm x 15mm USB stick microcontroller running JavaScript on STM32F401CDU6 84MHz ARM Cortex-M4 CPU with 384KB flash, 96KB RAM, 22 GPIO pins, on-board USB Type-A connector, and less than 0.05mA sleep current for multi-year battery operation.
• Original Espruino Board The original Espruino microcontroller board bringing JavaScript to microcontrollers; priced from £20 and the company's first product, successfully funded on Kickstarter in 2013.
• Bangle.js (v1) Hackable Smartwatch First-generation hackable, JavaScript-programmable smartwatch successfully funded on Kickstarter in 2018, predecessor to Bangle.js 2.
• Espruino Web IDE Free, open-source browser-based IDE for programming Espruino devices; provides syntax highlighting, code completion, debugging, automatic module loading, and a Blockly graphical editor; runs in the Chrome browser over Web Bluetooth.
• Bangle.js App Loader Free and open app store for Bangle.js smartwatches, hosting over 100 apps including games, navigation, fitness, watch faces, spirit levels, and QR code displays.

Quantifiable outcome

• Devices can run for years on a single battery charge due to single-chip architecture and low power consumption
• +2 more outcomes

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability6 records

Feature4 records

Partnerships

Six partnerships are on record, tiered core and minor.

• Nordic SemiconductorcoreTechnology or IntegrationNordic Semiconductor provides the nRF52 series ARM Cortex-M4 chips with integrated Bluetooth LE that power Espruino devices including Puck.js, Bangle.js, Pixl.js, Jolt.js, and MDBT42Q modules. This is a core technology partnership as Nordic's chips are fundamental to Espruino's product line.
• Raytac CorporationcoreTechnology or IntegrationRaytac manufactures the MDBT42Q Bluetooth LE module used in Espruino's Puck.js, Pixl.js, and Bangle.js products. Raytac's modules are pre-programmed with Espruino firmware before being incorporated into products.
• ST MicroelectronicscoreTechnology or IntegrationST Microelectronics provides STM32 ARM Cortex-M4 processors used in Espruino Pico and Espruino WiFi boards. Listed as a sponsor indicating ongoing technology partnership.
• Espressif SystemscoreTechnology or IntegrationEspressif's ESP8266 WiFi module is used for wireless connectivity in Espruino WiFi boards and as an add-on module for other Espruino boards. The ESP8266 provides 802.11 b/g/n WiFi capabilities.
• Smart Mobile StudiominorOthersListed as a sponsor on the Espruino website. Smart Mobile Studio is a Pascal-to-JavaScript compiler company. Nature of sponsorship is not detailed.
• Rockpile SolutionsminorOthersListed as a sponsor on the Espruino website. Nature of sponsorship is not detailed.

Scale indicators3 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Adafruit: Adafruit designs, manufactures, and sells open-source hardware including its own microcontroller boards (Feather, CircuitPython-capable) and accessories. Comparable as a maker-platform retailer with deep tutorial content and a curated online store.
• Raspberry Pi Foundation: Raspberry Pi's Pico microcontroller line and MicroPython support make it the most direct competitive alternative for hobbyists and educators. Comparable in target customer (makers, educators, embedded devs) and price range, but with vastly larger resources, education-channel reach, and ecosystem.
• SparkFun Electronics: SparkFun sells open-source microcontroller boards, sensors, and kits directly to makers and educators, similar to Espruino's distribution model. Comparable product mix (dev boards, accessories) and customer base.

Others

• Espressif Systems: Espressif supplies the ESP8266/ESP32 WiFi+BLE chips used in Espruino's WiFi board. Comparable as an upstream silicon partner, and a partial adjacent competitor via its own ESP32-S3 dev boards targeted at IoT makers.
• Nordic Semiconductor: Nordic Semiconductor supplies the nRF52 series BLE chips that power most of Espruino's product line. Comparable as an upstream enabling supplier rather than a competitor; Nordic's Thingy:91 and DK boards are partly comparable for embedded BLE developers.

Direct peers

• Arduino: Arduino is the dominant open-source microcontroller platform with a massive global community, hardware standard, and IDE. Directly comparable to Espruino as a maker/embedded development platform, though Arduino's ecosystem is C/C++-based rather than JavaScript-based.
• MicroPython: MicroPython provides a Python interpreter for microcontrollers and targets a near-identical developer persona — software engineers wanting a high-level language on microcontrollers. Directly comparable 'easy language on MCU' positioning, with significantly larger community momentum.

Emerging players

• Particle.io: Particle builds Wi-Fi/BLE-enabled IoT microcontrollers and a cloud platform targeted at connected product developers. Comparable on the BLE/IoT hardware side and partially overlapping customer base of embedded engineers building connected devices.
• Pimoroni: UK-based maker hardware vendor producing small, well-designed Raspberry Pi and microcontroller add-ons and standalone boards. Comparable as a boutique open-source hardware maker serving the hobbyist and educator segment, with similar scale to Espruino.
• Seeed Studio: Seeed Studio manufactures and distributes a broad line of open-source maker hardware including Wio Terminal, XIAO boards, and Grove sensors. Comparable in offering open-source microcontroller boards to makers and embedded developers, with strong distribution and a much larger catalog.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/Espruino
• GitHubgithub.com/espruino
• YouTubeyoutube.com/user/espruino
• Facebookfacebook.com/sharer.php?u=http://www.espruino.com&t=Espruino+JavaScript+for+Microcontrollers
• LinkedInlinkedin.com/company/espruino

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Espruino