ESP32Overview

ESP32-S31

The newest and most capable connected part in the family: RISC-V at 320 MHz, Wi-Fi 6, Bluetooth 5.4 with both LE and Classic, 802.15.4 and gigabit Ethernet — all on one die. In mass production since July 2026.

Everything, in one part. RISC-V, Wi-Fi 6, gigabit Ethernet.

Production Announced March 2026, mass production July 2026

$3.80 chip, from
CPU
Dual-core RISC-V with MMU, one core with a 128-bit SIMD data path
Clock
Up to 320 MHz (6.86 CoreMark/MHz)
Low-power core
Low-power RISC-V core, 40 MHz
On-chip SRAM
512 KB
PSRAM
External, up to 64 MB via 250 MHz 8-bit DDR
Flash
External via Octal SPI, up to 64 MB
Wi-Fi
Wi-Fi 6 (2.4 GHz)
Bluetooth
Bluetooth 5.4 — LE (LE Audio, Mesh 1.1, Direction Finding) + Classic
802.15.4
Yes — Thread and Zigbee
GPIO
60
USB
USB OTG
Deep sleep
Not yet published
Package
QFN 8×8
Reference dev board
ESP32-S31-Korvo-1 ($59)

Stands out for

The only part with Wi-Fi 6, BT 5.4 Classic+LE, 802.15.4 and 1000 Mbps Ethernet together; RAM-based PUF

Watch out for

Brand new — ecosystem, board availability and power figures are still maturing

Typical designs

Smart-home hubs, Matter gateways, industrial HMI, LE Audio devices

What is new here

The S31 is the most significant single release in the family since the original ESP32, for two reasons.

It moves the S-series to RISC-V. The S2 and S3 used Xtensa LX7 cores. The S31 uses two 32-bit RISC-V application cores at up to 320 MHz — and unusually, adds an MMU, which the rest of the family lacks. Espressif quotes 6.86 CoreMark/MHz, and one of the two cores carries a 128-bit SIMD data path for signal processing and quantised inference. A separate 40 MHz low-power RISC-V core handles background work.

It combines every radio Espressif ships into one part. Until the S31, choosing an ESP32 meant giving something up: Wi-Fi 6 meant no Bluetooth Classic; 802.15.4 meant no Ethernet; Ethernet meant the decade-old original. The S31 has Wi-Fi 6 on 2.4 GHz, Bluetooth 5.4 with both LE and Classic BR/EDR, IEEE 802.15.4 for Thread and Zigbee, and a 1000 Mbps Ethernet MAC. Nothing else in the family does more than two of those four.

The Bluetooth implementation is notably complete: LE Audio with the LC3 codec and multi-stream support, Bluetooth Mesh 1.1, Direction Finding, and Classic BR/EDR for legacy headsets, speakers and automotive head units. The dual I2S controllers include hardware-level Bluetooth audio synchronisation, which removes a genuinely fiddly class of software timing problem from audio products.

Multimedia and HMI

The S31 inherits and extends the S3’s display and camera capability rather than the P4’s:

  • DVP camera interface, 8 to 16-bit
  • LCD support at 8 to 24-bit parallel RGB, plus I8080 and MOTO6800
  • Hardware colour-space conversion between RGB565, YUV422, YUV420 and YUV411
  • A JPEG codec, a PPA (pixel processing accelerator) and 2D-DMA for compositing and scaling without burning CPU cycles
  • 14 capacitive touch channels
  • 60 GPIOs — the highest count in the family

Note what is not here: no MIPI-DSI or MIPI-CSI, and no H.264 encoder. For 1080p panels and video encoding the P4 remains the right chip. The S31 targets the large space below that, where a parallel-RGB panel and JPEG stills are sufficient.

Security

This is the strongest security package Espressif has shipped. In addition to the usual hardware AES-128/256, RSA, ECC, ECDSA and TRNG, the S31 adds:

  • A RAM-based PUF (physically unclonable function) for deriving a device-unique key from silicon variation, rather than storing one in fuses
  • An ECDSA-based digital signature peripheral that keeps private keys inaccessible to software
  • TEE and APM for hardware-enforced isolation between a trusted and an application domain
  • Flash and PSRAM encryption

For products facing the EU Cyber Resilience Act or similar regimes, the PUF plus TEE combination is materially easier to build a compliance argument around than the older parts.

Memory

512 KB of on-chip SRAM, with everything else external — but over fast buses. Flash goes out over Octal SPI to as much as 64 MB, and PSRAM over a 250 MHz 8-bit DDR interface, also to 64 MB, with simultaneous flash and PSRAM access. That last detail matters: on several older parts flash and PSRAM share a controller and contend.

Modules and boards

ESP32-S31-WROOM-3 modules are $5. Bare chips are ESP32-S31NRV16 and -NRV32 (16 or 32 MB PSRAM, QFN 8×8) at $3.80. The launch development board is ESP32-S31-Korvo-1 at $59, oriented towards audio and voice.

Espressif has committed ESP-IDF support along with ESP-Matter, ESP-BLE-AUDIO and ESP-GMF for multimedia, and integration with its ESP Private Agents platform for LLM-backed voice applications.

Choose it when

  • You need Wi-Fi 6 and Bluetooth Classic in the same product
  • You are building a Matter gateway or Thread border router with a wired uplink
  • You need gigabit Ethernet on an ESP32
  • You are building an LE Audio device
  • You need the strongest available security posture — PUF, TEE, PSRAM encryption

Choose something else when