Specifications:

• 802.11 b/g/n
• Wi-Fi Direct (P2P), soft-AP
• Integrated TCP/IP protocol stack
• Integrated TR switch, balun, LNA, power amplifier and matching network
•  Integrated PLLs, regulators, DCXO and power management units
• +19.5dBm output power in 802.11b mode
•  Power down leakage current of <10uA
• Integrated low power 32-bit CPU could be used as application processor
• SDIO 1.1/2.0, SPI, UART
• STBC, 1×1 MIMO, 2×1 MIMO
• A-MPDU & A-MSDU aggregation & 0.4ms guard interval
• Wake up and transmit packets in < 2ms
• Standby power consumption of < 1.0mW (DTIM3)

Warning: The ESP8266 works at 3.3V! Connecting directly to 5V will burn it!

You have to use voltage drivers or logic shifters.

Interface Details:

• SDIO 2.0, SPI, UART
• 32-pin QFN package
• Integrated RF switch, balun, 24dBm PA, DCXO, and PMU
• Integrated RISC processor, on-chip memory and external memory interfaces
• Integrated MAC/baseband processors
• Quality of Service management
• I2S interface for high fidelity audio applications
• On-chip low-dropout linear regulators for all internal supplies
• Proprietary spurious-free clock generation architecture
• Integrated WEP, TKIP, AES, and WAPI engines
• 32-pin QFN package
• Integrated RF switch, balun, 24dBm PA, DCXO, and PMU
• Integrated RISC processor, on-chip memory and external memory interfaces
• Integrated MAC/baseband processors
• Quality of Service management
• I2S interface for high fidelity audio applications
• On-chip low-dropout linear regulators for all internal supplies
• Proprietary spurious-free clock generation architecture
• Integrated WEP, TKIP, AES, and WAPI engines
• 32-pin QFN package
• Integrated RF switch, balun, 24dBm PA, DCXO, and PMU
• Integrated RISC processor, on-chip memory and external memory interfaces
• Integrated MAC/baseband processors
• Quality of Service management
• I2S interface for high fidelity audio applications
• On-chip low-dropout linear regulators for all internal supplies
• Proprietary spurious-free clock generation architecture
• Integrated WEP, TKIP, AES, and WAPI engines