ESP32 vs ESP32-S3: Specs, Performance & Which to Choose

If you are confused about whether to use an ESP32 or ESP32-S3 board for your project, this comparison will help you decide. Although their names are similar, choosing the wrong board can cause compatibility problems, extra development work and unnecessary cost. The better option depends on your project requirements. This article compares their practical differences, performance, software support, published project examples and important limitations.

Catalog

Figure 1. ESP32 and ESP32-S3 Development Boards

What Are ESP32 and ESP32-S3 Boards?

The terms ESP32 board and ESP32-S3 board refer to development boards based on Espressif microcontrollers. They are not single board models. Manufacturers offer different versions with varying modules, memory capacities, connectors and pin layouts.

Figure 2. ESP32 Development Board

What Is an ESP32 Board?

An ESP32 development board is built around an original ESP32 chip or module, such as the ESP32-WROOM-32. It combines the wireless microcontroller with supporting components for power, programming and connection to external circuits. Its input/output pins are normally exposed through headers, making the board suitable for developing and testing embedded systems, wireless devices and Internet of Things projects.

What Is an ESP32-S3 Board?

Figure 3. ESP32-S3 Development Board

An ESP32-S3 development board is built around an ESP32-S3 chip or module. The ESP32-S3 is a newer microcontroller designed for wireless embedded systems, USB devices, human-machine interfaces and workloads involving signal processing or small machine-learning models. These boards provide the supporting circuits needed to power and program the microcontroller and connect it to external hardware. Most available GPIO pins are exposed through headers for breadboard prototyping and custom circuit development.

ESP32 vs ESP32-S3 Specifications

This table compares chip-level specifications. Flash, PSRAM, connectors, exposed GPIOs and power consumption vary by development board.

Functional Block Diagram

Figure 4. ESP32 Functional Block Diagram

Figure 5. ESP32-S3 Functional Block Diagram

The official block diagrams show which functions are built into each chip. The original ESP32 includes Bluetooth Classic support, two DAC channels and an Ethernet MAC, but it has no native USB controller. The ESP32-S3 adds USB OTG, USB Serial/JTAG, GDMA, dedicated parallel LCD and camera interfaces, and additional security blocks such as HMAC, RSA digital-signature support and permission control. Its LX7 processor also includes SIMD instructions, although these are not labelled separately in the diagram. However, the S3 does not include the original ESP32’s DAC or Ethernet MAC. Compare these hardware blocks carefully because missing functions may require external components or software changes.

CPU and Memory Performance

Espressif reports 1,079.96 CoreMark for the dual-core ESP32 and 1,329.92 for the ESP32-S3, both at 240 MHz. The ESP32-S3 score is therefore 23.1% higher, although this does not guarantee the same improvement in every application.

The ESP32-S3 uses the newer Xtensa LX7 architecture and includes SIMD instructions for supported signal-processing and machine-learning operations. These instructions provide an advantage only when the code or library has been optimized to use them.

The ESP32 contains 520 KB of internal SRAM, while the ESP32-S3 contains 512 KB. These totals are not the amount of SRAM available to an application because firmware, wireless stacks, caches and system services also use internal memory. Some boards add external PSRAM, which increases capacity but is generally slower than internal SRAM and may not support every type of data or operation.

Wi-Fi and Bluetooth Differences

Both chips support 2.4 GHz IEEE 802.11b/g/n Wi-Fi with a specified maximum PHY rate of 150 Mbit/s. This value is not guaranteed application throughput. Actual speed and range depend on the antenna, board layout, interference, obstacles, protocol overhead and access point.

Figure 6. ESP32 and ESP32-S3 Wi-Fi and Bluetooth Differences

The main difference is Bluetooth support. The ESP32 supports Bluetooth 4.2 BR/EDR and Bluetooth Low Energy, while the ESP32-S3 supports Bluetooth 5 Low Energy only. The S3 provides a 2 Mbit/s PHY, coded PHY modes and extended advertising. However, it cannot use Bluetooth Classic profiles such as SPP and A2DP. Projects that depend on Classic Bluetooth must use the original ESP32 or migrate to BLE or another communication method.

Power Consumption and Runtime Estimation

Espressif lists typical chip-level values of approximately 0.8 mA in light sleep and 10 µA in deep sleep for the ESP32. For the ESP32-S3, the specified 240 µA light-sleep value assumes that Wi-Fi and VDD_SPI are powered down and the GPIOs are in a high-impedance state. Its deep-sleep current is approximately 8 µA when RTC memory and RTC peripherals remain powered, or 7 µA when only RTC memory remains powered.

These sleep-current figures were measured under different operating conditions and are not a direct board-to-board comparison. They also exclude the complete development board. Voltage regulators, USB bridges, power LEDs, PSRAM and connected components can increase current consumption. Wireless activity and processor wake time can also have a much greater effect on battery life than sleep current alone.

A simple estimate is:

Runtime in hours ≈ usable battery capacity in mAh ÷ average current in mA

Example: a 2,000 mAh battery powering a system with a measured average current of 10 mA provides approximately 200 hours, or 8.3 days, of ideal runtime before regulator and battery losses.

This formula assumes that capacity and current are measured on the same voltage side. Regulator losses, battery cut-off voltage, temperature and aging reduce the usable capacity. For the most reliable estimate, measure the average battery current during the finished system’s normal sleep, processing and wireless operating cycle.

USB, GPIO, and Peripheral Trade-Offs

ESP32 and ESP32-S3 development boards are not pin-compatible. Header positions, exposed GPIOs, strapping pins, USB connections and memory-reserved pins vary by board. Always check the exact board schematic before transferring existing wiring.

ESP32 DevKitC V4 vs ESP32-S3-DevKitC-1 Pinout Differences

Sources: Espressif’s official ESP32-DevKitC V4 guide and ESP32-S3-DevKitC-1 v1.1 guide.

Arduino and ESP-IDF Compatibility

Both the ESP32 and ESP32-S3 are officially supported by the Arduino-ESP32 core and ESP-IDF. In Arduino IDE, select the correct board and configure its flash, PSRAM, partition and USB settings. Basic Wi-Fi, GPIO, UART, I²C and SPI source code can often be reused, but the program must be compiled separately for each target.

In ESP-IDF, select the target before building:

• ESP32: idf.py set-target esp32

• ESP32-S3: idf.py set-target esp32s3

Source-code compatibility does not guarantee hardware compatibility. Board pin assignments, strapping pins, available memory and built-in peripherals can differ. A library may compile for both targets but still require different pin definitions, wiring or configuration. Code that depends on chip-specific hardware must also be changed.

Always confirm that third-party libraries support the selected chip and framework version. If compatibility was tested directly, record the exact Arduino-ESP32 version, ESP-IDF version, board model and library versions used. Do not add version numbers unless those versions were tested.

Real-World Project Case Studies

Fanariotis, Orphanoudakis, and Fotopoulos (2024) compared an ESP32 DevKit TTGO and ESP32-S3-DevKitC-1 using four identical ESP-DL models. Each test used one processor core, a 3.3 V supply, and a Keysight 34465A digital multimeter.

With the same 32 KB data cache, the two-stage human-face model took 419,556 µs on the ESP32 and 131,160 µs on the ESP32-S3. Their standby-subtracted energy values were 8.558 µWh and 3.166 µWh, respectively. Cat-face detection required 146,592 µs and 3.277 µWh on the ESP32, compared with 22,388 µs and 0.609 µWh on the ESP32-S3.

Figure 7. ESP32 vs ESP32-S3 Machine-Learning Energy Comparison. Source: Figure 5, Fanariotis, Orphanoudakis, and Fotopoulos (2024)

As shown in the figure, the ESP32-S3 used less processing energy across all four models when using SIMD/vector instructions. Its average power was higher, but the SIMD instructions completed inference much faster. However, the boards had different PSRAM configurations, and the tests excluded cameras and wireless communication. Trial counts and measurement variation were also not reported, so the results apply only to the tested workloads.

Which Chip Should You Choose?

Development-board memory, exposed pins, USB ports and connectors vary. Check the exact board schematic before making the final choice.

Technical References

• Espressif Systems. ESP32 Series Datasheet, Version 5.3, July 2026.

• Espressif Systems. ESP32-S3 Series Datasheet, Version 2.2, March 2026.

• Espressif Systems. Arduino-ESP32 Programming Guide.

• Espressif Systems. ESP-IDF Programming Guide: ESP32 Getting Started.

• Espressif Systems. ESP-IDF Programming Guide: ESP32-S3 Getting Started.

• Espressif Systems, Arduino-ESP32 Supported SoCs.

• Fanariotis, A., Orphanoudakis, T., and Fotopoulos, V. (2024). “Reducing the Power Consumption of Edge Devices Supporting Ambient Intelligence Applications.” Information, 15(3), 161.

Frequently Asked Questions [FAQ]

1. Is ESP32-S3 faster than ESP32?

Espressif reports a dual-core CoreMark score that is 23.1% higher for the ESP32-S3 at 240 MHz. However, the actual improvement depends on the workload. Applications optimized for its SIMD/vector instructions may gain more, while other applications may show a smaller difference.

2. Does ESP32-S3 support Bluetooth Classic?

No. The ESP32-S3 supports Bluetooth 5 Low Energy only. Projects requiring Bluetooth Classic profiles such as SPP or A2DP should use the original ESP32 or another compatible chip.

3. Can 5 V sensors connect directly to ESP32 and ESP32-S3 GPIO pins?

Not if the sensor outputs a 5 V signal. Both devices use 3.3 V logic, so a voltage divider or level shifter is required for 5 V outputs. Also ensure that I²C pull-up resistors connect to 3.3 V, not 5 V.

4. Can ADC2 measure a sensor while Wi-Fi is active?

ADC2 shares hardware resources with Wi-Fi on both chips. ESP32 ADC2 access can be blocked, while ESP32-S3 ADC2 readings may fail during Wi-Fi operation. Use ADC1 for reliable Wi-Fi-connected sensor measurements.

5. Does a 12-bit ADC guarantee accurate voltage measurements?

No. Twelve-bit resolution provides 4,096 output levels, but noise, reference-voltage variation, attenuation and circuit design affect accuracy. Use ADC calibration, averaging and input filtering, or an external precision ADC when measurement accuracy is important.

6. Does adding PSRAM make an ESP32 or ESP32-S3 faster?

PSRAM increases memory capacity but is generally slower than internal SRAM. It is useful for camera frames, display buffers and machine-learning data, while time-critical code, DMA descriptors and frequently accessed data should remain in internal memory.

7. Which chip provides stronger security for a commercial IoT product?

Both support secure boot and flash encryption, but the ESP32-S3 adds features such as hardware-assisted digital signatures, HMAC and improved memory protection. These protections must be correctly configured; choosing the S3 alone does not make a device secure.