Happy Bison

List of ESP8266-based modules

There are several modules based on ESP8266 WiFi SoC. Each has its own field of use and functionality, although some look similar to others. The list mainly consists of ESP-xx variations of such modules which are widely available from online stores like eBay, Aliexpress, Tao, etc.

ESP-01

I believe this is one of the first versions of ESP8266-based module produced in large quantities. This is probably how it started.

It's simple and has limited number of GPIO pins, but it's still useful to get started. The 2.54mm-pitch 8-pin dual row header makes experimenting easier. Some early versions of ESP-01 (sometimes called V080) did not have any GPIO pins connected on the header, you get RX/TX and power only.

The size of the module is 14.3mm x 24.8mm. It has PCB antenna. All you need to do is to connect power, tie CH_PD pin high and you are ready to go.

Some early ESP-01 board had a wrong LED current limiting resistor which caused the LED to burn.

ESP-02

This is one of the smallest ESP8266 modules available. The size of ESP-02 is 14.2mm x 14.2mm. It has no antenna, but it comes with U.FL/IPEX antenna connector.

The same 8 pins as ESP-01, but layed out as plated half-holes on the side of the board. That makes it friendly for surface soldering on other boards.

ESP-03

ESP-03 is ESP8266 board with ceramic antenna manufactured by Rainsun. The module has 14 pins as half-holes located on the sides for surface soldering similar to ESP-02. One of the pins can be used to connect external antenna.

The size is 17.4mm x 12.2mm.

ESP-04

This is very similar to ESP03 -- 14 pins as half-holes, but without integrated antenna or connector for it. It also has a pin to solder external antenna.

That makes this board almost as small as ESP-02, the size is 14.7mm x 12.1mm.

ESP-05

A breadboard friendly ESP8266-based board with U.FL/IPEX connector for external antenna. There are two variations of this board: 5 pins and 4 pins. Each variation is 14.2mm x 14.2mm. The pins are 2.54mm pitch.

The 4 pins board has GND, RX/TX and power. The 5 pins version adds Reset pin.

ESP-06

One of the smallest boards. It has 12 signal solder pads, and several ground pads. The module has no built-in antenna or connector, you have to solder it to one of the pads. It also comes with a metal shield and FCC logo.

The size is 14.2mm x 14.7mm.

ESP-07

Another module with a metal shield and FCC logo on it. The module has ceramic antenna built-in and U.FL/IPEX connector additional to it. It has 16 pins made as half-holes and smaller holes, so you could either solder it as surface mount or use 2mm pitch pin headers. Some earlier batches of ESP-07 had 14 pins only.

There were some ESP-07 modules with oscillator incorrectly soldered (turned 90 degrees) which caused the module not to boot. There are reports that some ESP-07 boards have GPIO 4 and 5 switched.

The size is 22mm x 16mm. The older version of ESP-07 with 14 pins is 20mm x 16mm.

ESP-08

This board is similar to ESP-06 -- it has metal shield and no antenna. It has 14 pins as half-holes with 2mm pitch.

The size is 17mm x 16mm.

ESP-09

This is the tiniest ESP8266-based module. It has 12 signal pads and ground pads for soldering. Signal pads are 1.9mm pitch. There is no antenna on it, it must be soldered externally using one of the signal pads. This board has flash chip with increased capacity of being 1MiB compared to 512KiB on other modules.

The size is 10mm x 10mm.

ESP-10

Another small module without antenna or connector for it. It has 5 pins (Power, GND, RX/TX and Reset) as half-holes.

The size is 14.2mm x 10mm.

ESP-11

This board has ceramic antenna and 8 pins as half-holes with smaller holes for surface soldering or header mounting. Pins are 1.27mm pitch.

The size is 19.3mm x 13mm.

ESP-12 series

ESP-12 modules have metal shield with FCC logo on it. It appears these modules are FCC approved (FCC ID: 2ADUIESP-12). The modules have 16 pins and PCB antenna. Similar to ESP-07, some ESP-12 boards have GPIO 4 and 5 switched.

The size is 24mm x 16mm.

The newer ESP-12-E module adds 5 more half-hole (without extra hole) pins on the side. There are also two more variations of ESP-12-E module: ESP-12-D and ESP-12-Q. Probably referring to Dual and Quad SPI operations for Flash chip because ESP-12-D frees up GPIO 9 and GPIO 10 which are usually occupied for Quad mode SPI operations.

ESP-13

One of the newest ESP8266 modules. It has 18 half-hole pins with 1.5mm pitch. It has metal shield with FCC logo and PCB antenna. Some variations have "ESP_WROOM_02" written on the PCB.

The size is 20mm x 18mm.

ESP-100

Claimed to be ESP-07 compatible, but with 8Mb flash and external antenna (U.FL/IPEX connector). There is a solder placeholder for a ceramic antenna.

The size is 21mm x 16mm.

ESP-201

I got ESP-201 is a part of Dev kit I bought in the past. It has 26 pins broken into 2 x 11 pins and 1 x 4 pins headers. All are 2.54mm pitch. However, this module is not breadboard friendly because of the extra 4 pins headers (unless you remove it or do some other hack). It has PCB antenna and U.FL/IPEX connector. You can switch between PCB antenna and connector by moving 0 ohms resistor (the default is to use U.FL/IPEX connector). The board has white color. The size is 35mm x 25mm.

ESP-WROOM-01

This module is being produced by Espressif. It has dual-row 2x9 pin header soldered. It has wire antenna.

The size is 11.5mm x 11.5mm (without pin header).

ESP-WROOM-02

This is completely identical to ESP-13 module as mentioned above. The same 18 half-hole pins with 1.5mm pitch, PCB antenna and 20mm x 18mm size.

Comparison table