Espressif’s ESP32 family has exploded with variants, but for most makers and IoT projects the real question is simple:
Should I use the classic ESP32, or the newer ESP32-S3?
Both chips are dual-core Wi-Fi + Bluetooth SoCs, both are cheap, and both are very well supported in Arduino and ESP-IDF. But there are important differences in CPU architecture, peripherals, AI acceleration, USB support, and power that can make one a much better fit for your project.
This guide compares ESP32 (original, ESP32-WROOM / WROVER) vs ESP32-S3, and ends with practical “choose this if…” scenarios.
1. Quick comparison table
| Feature | ESP32 (original) | ESP32-S3 |
|---|---|---|
| CPU architecture | Dual-core Xtensa LX6 | Dual-core Xtensa LX7 |
| Max clock | Up to 240 MHz | Up to 240 MHz |
| Instruction set extras | FPU, DSP | FPU, DSP + vector (SIMD) instructions for AI |
| Wi-Fi | 2.4 GHz 802.11b/g/n | 2.4 GHz 802.11b/g/n |
| Bluetooth | Classic + BLE 4.2 | BLE 5.0 (LE), no classic |
| USB (built-in) | None | Full-speed USB OTG (device/host) on some packages/boards |
| PSRAM support | External PSRAM on many modules | Optional external PSRAM, similar concept |
| Flash | External SPI flash (4–16 MB typical) | External SPI flash (4–16 MB typical) |
| ADC quality | 12-bit, non-linear, noisy | 12-bit, improved but still not “laboratory grade” |
| GPIO count | 34 GPIO (not all exposed) | 45 GPIO (not all exposed) |
| AI / ML acceleration | None | SIMD instructions, optimized for AI (tiny models, DSP) |
| Target use | General IoT, Wi-Fi, BT Classic, audio, legacy projects | Vision / voice / USB-based devices, modern BLE, AI at the edge |
The core idea:
- If you need Bluetooth Classic (A2DP audio, SPP serial, etc.) → ESP32 (original).
- If you need USB, BLE 5, better AI/DSP, or want a “newer” long-term platform → ESP32-S3.
2. CPU & performance
Both chips run up to 240 MHz, but the core itself is newer on the S3.
ESP32 (original)
- Dual-core Xtensa LX6, 32-bit
- Good general performance for Wi-Fi, networking, basic DSP
- Widely used in hobby projects and products – huge ecosystem
ESP32-S3
- Dual-core Xtensa LX7, 32-bit
- Supports vector (SIMD) instructions specifically designed to accelerate:
- DSP (audio processing, filtering)
- Tiny machine learning / AI workloads (keyword spotting, small CNNs, etc.)
- Similar clock speed, but more efficient for code that uses the vector unit
What this means in practice
- For “normal” Arduino-style projects (sensors, MQTT, web UI), performance feels similar.
- For audio, signal processing, or TensorFlow Lite Micro, ESP32-S3 can be significantly faster or more power efficient, if you use libraries that take advantage of its vector instructions.
3. Wi-Fi and Bluetooth differences
Wi-Fi
Both chips:
- Use 2.4 GHz Wi-Fi (802.11 b/g/n)
- Have similar throughput and range for typical IoT use
For most hobby projects, Wi-Fi is effectively “the same” between ESP32 and S3.
Bluetooth
This is where things diverge:
- ESP32 (original)
- Supports Bluetooth Classic and BLE 4.2.
- You can use:
- Classic profiles like A2DP (audio streaming)
- SPP for simple serial over BT
- Useful for legacy Android support, older devices, audio gateways, etc.
- ESP32-S3
- Supports Bluetooth Low Energy 5.0 (LE)
- No Bluetooth Classic.
- Better suited for modern BLE beacons, BLE sensors, BLE HID (keyboards, etc.).
So:
- If your project needs Bluetooth audio or classic serial over BT, choose ESP32.
- If you’re building a BLE peripheral (sensors, HID, BLE Mesh, etc.), ESP32-S3 is the better, more modern choice.
4. USB – the killer feature of ESP32-S3
This is one of the biggest practical differences.
ESP32 (original)
- No native USB controller in the chip.
- Boards typically have an external USB-to-Serial bridge (CP2102, CH340, FTDI, etc.) used only for flashing and serial monitor.
- You cannot easily make the ESP32 appear as a USB keyboard, USB microphone, USB audio device without extra hardware.
ESP32-S3
- Integrates USB 2.0 Full-Speed OTG in the chip (in certain packages).
- On boards like ESP32-S3-DevKitC, there is often no external USB-UART – the S3 itself handles USB-Serial and USB-JTAG.
- You can make it appear as:
- USB CDC (serial)
- USB HID (keyboard, mouse, gamepad)
- USB MIDI, etc.
- In host mode it can talk to:
- USB flash drives
- Some cameras
- HID devices (keyboards, mice)
If your project says “it connects via USB directly to a PC as X”, ESP32-S3 is the obvious choice.
5. Memory (Flash & PSRAM)
Both families use external SPI flash (commonly 4–16 MB on modules) and support external PSRAM for RAM-hungry applications (graphics buffers, AI, etc.).
- ESP32-WROVER modules → ESP32 with PSRAM on board (typical 4–8 MB).
- ESP32-S3-WROOM / S3-WROOM-1 → some SKUs with PSRAM, some without.
For typical web / MQTT / sensor projects, 4 MB flash + no PSRAM is plenty.
For heavy stuff:
- Web servers with big UI
- Cameras, displays, AI, FFT, or audio buffers
…you want a module/board with PSRAM, and ESP32-S3 is usually preferred for new designs.
6. ADC, DAC and peripherals
ADC
The original ESP32 ADC is infamous: it works, but:
- Non-linear
- Noisy
- Requires calibration and careful scaling if you want accurate readings
ESP32-S3’s ADC is significantly improved (though still not perfect lab-grade). For serious analog work you still typically use an external ADC like ADS1115, but for general sensors the S3 behaves a bit better.
DAC
- ESP32 has 2 basic 8-bit DAC channels (GPIO25, GPIO26).
- ESP32-S3 has no built-in DAC, you use external DACs or PWM + filter instead.
If you really need on-chip analog output, original ESP32 is handy. For most modern work, external DACs or class-D audio amps are better anyway.
Other peripherals
Both families have:
- Multiple UARTs, I²C, SPI
- RMT (great for NeoPixels / IR)
- I²S (audio), timers, PWM, etc.
ESP32-S3 adds:
- More GPIOs
- Some extra internal features aimed at voice / vision (e.g. LCD interface, better integration with external PSRAM and camera modules compared to the original ESP32’s ESP32-CAM style approach).
7. Power consumption
At high level, both are not ultra-low-power MCUs like tiny Cortex-M0+ chips, but both offer:
- Modem sleep, light sleep, deep sleep
- RTC memory and wakeup sources (timer, GPIO, ULP, etc.)
ESP32-S3 benefits from later-generation silicon and can be slightly more efficient for some workloads, but in many real projects board design and Wi-Fi usage dominate power consumption.
If your power budget is extremely tight, you might look at ESP32-C3 / C6 / H2 instead of these two.
8. Ecosystem, tools and support
Both chips are:
- Supported in Arduino and ESP-IDF
- Supported by PlatformIO, MicroPython, etc.
- Have many DevKit and NodeMCU-style boards.
However:
- A lot of older tutorials and libraries on the internet assume “classic ESP32” (WROOM/DevKitC).
- Newer examples from Espressif, especially for USB, AI and camera, often target ESP32-S3 by default.
For a new project, you won’t struggle with either. For copy-pasting older code, the original ESP32 might match more closely, but S3 support has caught up very well.
9. So… which one should you pick?
Here’s the practical decision guide.
Choose ESP32 (original) if:
- You explicitly need Bluetooth Classic:
- A2DP audio streaming
- Classic SPP serial (some legacy Android apps)
- You want to reuse lots of older ESP32-WROOM-based code and tutorials with minimal friction.
- You want simple analog output via the on-chip 8-bit DAC.
- You’re using an existing design / shield that was made specifically for original ESP32 and don’t want to adjust pin mapping.
Typical examples:
- Bluetooth audio receiver / transmitter
- Retro projects using BT SPP as a serial link
- Simple IoT boards already in production (no reason to change yet)
Choose ESP32-S3 if:
- Your project will connect to a PC / phone as a USB device:
- USB serial
- USB HID keyboard / mouse / gamepad
- USB MIDI
- You want BLE 5 capabilities and only need BLE (not classic BT).
- You plan to do AI / ML / DSP (voice detection, keyword spotting, small image classification) and want the benefit of vector instructions.
- You want a design that’s more “future-proof”, as Espressif’s newer devkits, camera boards, and AI demos tend to focus on S3.
- You don’t care about on-chip DACs and are happy to use PWM or external DACs.
Typical examples:
- USB-C development boards that show up as a serial device + HID keyboard
- Smart speakers / voice assistants with wake-word detection
- Camera / vision projects that are not yet on pure ESP32-P4 territory
- Human-machine interfaces (TFT + touch, USB + BLE)
10. TL;DR summary
- ESP32 (classic) is still a great all-rounder:
- Wi-Fi + BT Classic + BLE 4.2, basic DAC, tons of examples.
- Best when you need Bluetooth Classic or you’re extending an older design.
- ESP32-S3 is the better default for new designs:
- Wi-Fi + BLE 5, built-in USB, more GPIOs, AI-friendly vector instructions, better ADC.
- Best when you care about USB, modern BLE, AI, cameras, and long-term support.