Both ESP32-S2 and ESP32-S3 are “second-wave” ESP32 chips: they add native USB and more modern security features compared to the original ESP32. But they target slightly different use cases:
- ESP32-S2 → Wi-Fi-only, single-core LX7, USB OTG, no Bluetooth
- ESP32-S3 → Wi-Fi + BLE 5, dual-core LX7, USB OTG, plus AI/vector instructions
If you’re deciding what to base a new board or project on, it’s worth understanding where each shines.
1. Quick comparison table
| Feature | ESP32-S2 | ESP32-S3 |
|---|---|---|
| CPU | Single-core Xtensa LX7, up to 240 MHz | Dual-core Xtensa LX7, up to 240 MHz |
| Wi-Fi | 2.4 GHz 802.11 b/g/n | 2.4 GHz 802.11 b/g/n |
| Bluetooth | None | Bluetooth 5 (LE) – no Classic BT |
| USB | Full-speed USB OTG (device/host) | Full-speed USB OTG (device/host) |
| AI / vector accel | No dedicated AI instructions | Vector (SIMD) instructions for AI/DSP |
| GPIO (max) | Up to 43 GPIOs (not all on modules) | Up to 45 GPIOs (not all on modules) |
| Camera / LCD support | Parallel LCD & camera interfaces | Parallel LCD & camera interfaces + more GPIO width |
| Typical role | Wi-Fi + USB devices, secure IoT, panels | AIoT, vision/voice, Wi-Fi + BLE, USB gadgets |
High-level take:
- If you need BLE + dual core + AI extras → ESP32-S3.
- If you want a simple, Wi-Fi-only USB device and cost/power matter → ESP32-S2.
2. CPU & performance
ESP32-S2
- Single-core Xtensa LX7 @ up to 240 MHz.
- Enough for web servers, USB gadgets, and typical Wi-Fi IoT nodes.
- Because it’s single-core, all tasks share the same core (Wi-Fi, USB, your app).
ESP32-S3
- Dual-core Xtensa LX7 @ up to 240 MHz.
- Extra vector instructions to speed up:
- Neural nets (e.g. keyword spotting, small CNNs)
- DSP workloads (FFT, filters, audio effects)
Implication in real projects:
- For “normal” IoT (sensors, REST, MQTT, small web UI), both feel fine.
- If you want camera + web + Wi-Fi + some ML, or any heavier multitasking, S3’s second core + SIMD are a big quality-of-life improvement.
3. Connectivity: Wi-Fi & Bluetooth
Wi-Fi – roughly equal
Both:
- 2.4 GHz 802.11 b/g/n
- Integrated RF, PA, LNA, etc., full IoT-grade Wi-Fi.
No major difference here for typical use.
Bluetooth – S3 wins by default
- ESP32-S2:
- No Bluetooth at all – strictly Wi-Fi only.
- ESP32-S3:
- Bluetooth 5 (LE) (Coded PHY, 2M PHY, extended advertising).
- No Classic BT, but great for:
- BLE sensors / beacons
- BLE HID (keyboards, gamepads, remotes)
- BLE + Wi-Fi bridges
So if your project needs any Bluetooth, ESP32-S3 is the only option between these two.
4. USB: both have it, but S3 integrates better with AI / vision use
ESP32-S2
- First ESP chip with native USB OTG (Full-Speed USB 2.0).
- Great to implement:
- USB-CDC serial
- HID devices (keyboard, mouse)
- Simple WebUSB gadgets
ESP32-S3
- Also has Full-Speed USB OTG with integrated transceiver.
- Many dev boards use it directly as:
- USB-Serial/JTAG for flashing + debug
- USB device functions (CDC, HID, etc.)
Practically: for USB-only / USB-centric devices, both S2 and S3 are good choices.
The decision then comes down to “Do you also want BLE / dual core / AI?” → that points to S3.
5. GPIOs, memory, and peripherals
GPIOs & I/O
- ESP32-S2: up to 43 GPIOs; includes:
- Capacitive touch inputs
- Parallel LCD & camera interfaces.
- ESP32-S3: up to 45 GPIOs; similarly:
- Touch inputs
- 8-/16-bit parallel interfaces for LCDs and cameras (improved vs S2 for some use cases).
Module/devkit pinouts vary, but S3 generally gives you a bit more flexibility for displays/cameras.
Memory (Flash & PSRAM)
Both:
- Use external SPI flash (commonly 4–16 MB on modules).
- Have variants with integrated PSRAM (WROVER/WROOM-type modules).
S3 modules with PSRAM are especially nice for:
- Camera frame buffers
- Graphics frame buffers (TFTs)
- Audio processing
- TinyML models
For “classic” HTTP + MQTT + a few sensors, either is fine with 4 MB flash and no PSRAM.
6. Camera, LCD & “AIoT” angle
Both S2 and S3 are meant to be HMI / multimedia-capable, but the S3 is the evolution.
ESP32-S2
- Parallel interfaces for LCD RGB and camera.
- Often used in:
- USB + display control panels
- Simple streaming cameras
- Wi-Fi touch interfaces
ESP32-S3
- Similar LCD/camera capabilities, but:
- More GPIOs for wide data buses
- Dual core + vector instructions suited for on-device AI:
- Face detection/tracking
- Keyword spotting
- Lightweight classification
If your vision/voice project is “just capturing and streaming,” S2 can do it.
If you want to process data locally (AI at the edge), S3 is strongly preferable.
7. Power and use cases
Both S2 and S3:
- Support light sleep and deep sleep modes
- Can wake up via timers, GPIO, etc.
S2 is marketed as a low-power secure Wi-Fi MCU – for pure Wi-Fi sensor hubs it can be marginally simpler and slightly cheaper.
S3’s power draw can be higher when both cores + radios are active, but in realistic IoT duty cycles, firmware design and radio usage matter more than the chip choice.
8. Which one should you choose?
Pick ESP32-S3 if:
- You need Bluetooth Low Energy (BLE 5) as well as Wi-Fi.
- You want dual-core for heavier multitasking (web server + camera + logic).
- You plan to do AI / ML / DSP at the edge (voice, simple vision, sensor fusion).
- You want a more “future-proof” platform – Espressif’s recent devkits and AI/vision demos are mostly S3-based.
Typical S3 projects:
- Smart camera with local face detection
- USB + BLE HID (macro keypad with RGB + screen)
- Voice assistant / wake-word device
- Rich HMI panel with TFT + touch + Wi-Fi + BLE
Pick ESP32-S2 if:
- You only need Wi-Fi + USB, no Bluetooth.
- Cost and simplicity are more important than max performance.
- You’re building:
- USB gadgets (WebUSB, USB HID, USB-CDC)
- Wi-Fi control panels or sensor hubs
- Low-power secure Wi-Fi devices with a relatively light application load.
Typical S2 projects:
- USB-connected IoT debug dongle
- Wi-Fi + USB configuration tools
- Simple Wi-Fi display panels or USB-configurable data loggers
9. TL;DR
- ESP32-S3 = S2 on steroids: dual-core, BLE 5, AI/vector acceleration, more GPIO, still has USB OTG.
- ESP32-S2 = lean Wi-Fi + USB chip: single core, cheaper/simpler, no Bluetooth, still good for secure Wi-Fi devices and USB gadgets.