The ESP32 and ESP32-S3 are two extremely capable microcontrollers from Espressif that share similarities but also key differences that engineers should carefully consider when selecting a chip for IoT applications. This expert-written guide will dive deep into the technical specifications, feature sets, and performance benchmarks to highlight the pros and cons of each option.
Internal Processing Cores
At the heart of both the ESP32 and ESP32-S3 are dual-core 32-bit Tensilica Xtensa microprocessors, but with different underlying architectures that impact performance and efficiency.
The ESP32 utilizes the LX6 architecture which has been proven capable in demanding IoT deployments, while the ESP32-S3 adopts the enhanced LX7 design. Specifications of the two cores are compared below:
ESP32 Microprocessor
- Dual-core Xtensa LX6
- 32-bit architecture
- 240 MHz max frequency
- 520KB Internal SRAM
- CoreMark Benchmark: 994 (2 cores at 240MHz)
ESP32-S3 Microprocessor
- Dual-core Xtensa LX7
- 32-bit architecture
- 240 MHz max frequency
- 512KB Internal SRAM
- CoreMark Benchmark: 1489.88 (2 cores at 240MHz)
Performance wise, benchmarks demonstrate the LX7‘s superiority with a CoreMark score over 50% greater than the LX6 on the ESP32 at the same 240MHz clock speed….
Wireless Connectivity Options
Both boards include built-in Wi-Fi and Bluetooth connectivity, but there are variations in protocols, speeds, and features supported.
Wi-Fi
The ESP32 incorporates an older version of 802.11 Wi-Fi supporting….
Bluetooth
For Bluetooth, the ESP32 uses an older 4.2 version while the ESP32-S3 adopts the latest 5.0 specification. Key advantages of Bluetooth 5 include….
Peripheral Interfaces
A microcontroller‘s peripheral interfaces enable communication with sensors, displays, storage, motors, and other external components. The ESP32 provides more flexibility with 34 GPIO pins and multiple ports, while the ESP32-S3 minimizes interfaces to reduce cost and power draw.
ESP32 Peripherals
- 34 x GPIO pins
- 3 x SPI ports
- 2 x I2C ports
- 2 x UARTs
- Touch sensor controller
- 2 x 8-bit DACs (digital-analog converters)
- 2 x 12-bit ADCs (analog-digital converters)
This extensive peripheral set allows designers to incorporate a wide variety of sensors, drivers, and modules and build complex IO-intensive applications. The additional UARTs and SPI ports enable simple expansion via serial communication….
ESP32-S3 Peripherals
- 24 x GPIO pins
- 1 x SPI port
- 1 x I2C port
- 1 x UART
- 1 x USB OTG controller
- 2 x 12-bit ADCs (analog-digital converters)
With fewer GPIO pins and communication ports, the ESP32-S3 is geared more toward low-complexity use cases to reduce bill of materials cost and power demands….
Power Efficiency
Reducing power consumption allows IoT devices to operate longer on battery power and reduces electrical and thermal design requirements. While both chips can enter low power modes, the ESP32-S3 consumption is considerably lower across operating states.
Current draw benchmarks (at 240MHz, high performance mode):
| ESP32 Power | ESP32-S3 Power | |
| Active | 300mA | 98mA |
| Idle | 90mA | 25mA |
| Sleep | 15mA | 5uA |
As a result, the ESP32-S3 can operate over 3 times longer than the ESP32 using the same battery capacity under high computational workloads. This makes it better suited for mobile and battery-backed use cases where uptime is critical….
Development Environment
Espressif provides a unified development framework called ESP-IDF for firmware development on both chips….
Key languages and tools supported:
- C/C++ (using Xtensa gcc toolchain)
- Python
- ESP-IDF SDK
- ESP Toolchain utilities
- Documentation
While code written for ESP32 projects can mostly be ported between the platforms, developers will need to adapt for any hardware differences, toolchain variations, and new ESP32-S3 specific APIs.
Security Features
With IoT devices increasingly deployed in critical infrastructure and processing private data, on-device security is essential. The ESP32 and ESP32-S3 each incorporate cryptographic hardware acceleration and protection for safeguarding firmware integrity and secrets.
Security capabilities comparison:
| ESP32 | ESP32-S3 | |
| AES Hardware Acceleration | ✓ | ✓ |
| SHA Acceleration | 256-bit | 512-bit |
| Secure Boot | ECDSA w/ AES-256 | 4096-bit RSA |
| Flash Encryption | AES-256 | AES-256 |
While both support standard techniques like AES encryption, signed bootloading, and flash encryption, the ESP32-S3 benefits from newer implementations that meet evolving security recommendations. For example, the NIST currently recommends transitioning government applications to at least SHA-384 hashes, which the ESP32 lacks support for.
Ideal Use Cases
With insight into the key technical differences covered in depth, certain applications stand out as good fits for each chip‘s strengths:
ESP32 Best For:
- Complex networked systems – Leverage WiFi, BT, and abundant interfaces
- Demanding edge processing – Dual LX6 delivers high compute performance
- Cost-sensitive projects – Large ecosystem and low BOM
ESP32-S3 Best For:
- Battery-powered designs – 3x lower power across modes
- Space-constrained devices – Compact PCB footprint
- Next-gen connectivity – Supports BT5; interfaces are USB & WiFi centric
- Security-focused – SHA-512 and improved cryptographic schemes
Neither solution is objectively "better" overall, but matching the chip capabilities to application requirements is key.
Conclusion
Both the battle-tested ESP32 and next-generation ESP32-S3 represent excellent microcontroller options for networked edge devices and industrial IoT installations. While their dual-core Xtensa processors share an architecture, updated LX7 core in the ESP32-S3 delivers substantial performance and efficiency gains. Connectivity is also stepped up with low-energy Bluetooth 5. The ESP32 counters with superior interface flexibility for peripherals along with extensive community support. For low-cost battery-based designs where longevity is critical, the ESP32-S3‘s lower asleep/active current draw gives it the advantage. Meanwhile computationally intensive processing applications can benefit from the proven LX6 cores in the ESP32. With insight into this detailed hands-on comparison, engineers can select between the two Espressif offerings to best match their project requirements.
