Variants

How the family is organised

“ESP32” is a family name, not a part number. The suffix after it tells you which line a chip belongs to, and the line tells you what trade-off Espressif made:

A second, orthogonal split matters just as much. The original ESP32, the S2 and the S3 use Espressif’s licensed Xtensa cores. Every part designed after them — the whole C, H, P and E series, and the new S31 — uses RISC-V. In practice this rarely affects application code, because ESP-IDF abstracts it, but it does affect toolchains, assembly-level optimisation and the availability of third-party runtimes.

Complete comparison

Cores counts high-performance cores; “+ LP” means a separate low-power core or ULP coprocessor is also present. USB distinguishes real OTG (which can implement USB device classes) from a Serial/JTAG peripheral (which cannot) — see Specifications. From is Espressif's published reference sample price for the cheapest orderable part number in the series and excludes flash and PSRAM options. Sleep currents are typical values, some estimated rather than characterised.

The lineup, by line

What the table does not tell you

A specification table flattens some genuinely important distinctions. Four worth knowing before you commit to a part:

“USB” means three different things. The S2 and S3 have real USB OTG, but only at Full Speed (12 Mbps). The P4 has a High Speed controller (480 Mbps) and a Full Speed one and a serial/JTAG unit. Most C and H parts have only a USB Serial/JTAG peripheral — excellent for flashing and debugging without an external adapter, useless for implementing a USB device class. The original ESP32 has no USB at all.

“Hardware ECC” is not one feature. The C6 has a genuinely separate ECC accelerator block that measurably speeds up ECDSA signing and ECDH. The S3 is also marked as having ECC, but its operations run through the general-purpose bignum unit. Both get a tick in a comparison table; their performance differs by an order of magnitude. Details are in Specifications → security .

Deep-sleep figures are not equally trustworthy. Some are characterised datasheet values; others, particularly for the newest parts, are Espressif estimates extrapolated from similar silicon. Treat single-microamp differences between chips as noise until you measure your own board.

Announced is not available. Two of the fourteen parts here — the H21 and the H4 — are sampling rather than in volume production, and the E22 is not a microcontroller you can design in alone. The status badge on each row reflects this.

Also in the family, but not an ESP32

Three part numbers cause regular confusion:

• ESP8266 — the 2014 predecessor. Single Tensilica L106 core, 160 KB RAM, Wi-Fi only, no Bluetooth. Still sold and still supported, but there is no good reason to start a new design on it when the C2 and C3 cost the same and are dramatically more capable.
• ESP8684 — this is an ESP32-C2. Espressif sells the flash-integrated version of the C2 die under the ESP8684 name, which is why the C2 appears to have no in-package flash while ESP8684 modules clearly do.
• ESP8685 — likewise an ESP32-C3 variant sold under a different part number.

The naming is a historical artefact of how the parts were positioned commercially, not a difference in silicon family. See Boards & modules for the full decoder.

Every variant in detail

One page per SoC, each with the full specification, what it is genuinely good at and where it falls down.