Eleven Espressif chips side by side, with every chip variant listed. Specs are for the bare chip; a module or dev board may expose fewer pins and adds its own flash and PSRAM.
Answer a few questions about what you're building. Hard requirements rule chips out; the rest decides the order. If a question doesn't matter for your project, choose Doesn't matter to skip it. Not-recommended chips (ESP8266) are never suggested.
Variants: part numbers differ only in what's inside the package. F = in-package flash, R = in-package PSRAM, the number is the size in MB (FH4 = 4 MB flash, R8 = 8 MB PSRAM). EOL and NRND parts are listed because they still turn up on boards; don't design them in.
Flash and PSRAM: chips without in-package flash use an external SPI flash chip, which the module or board adds. Typical modules carry 4–16 MB.
GPIO: the chip's programmable GPIO count. Some pins are strapping pins, input-only or taken by flash/PSRAM, so a dev board exposes fewer.
Wi-Fi 4 = 802.11 b/g/n. Wi-Fi 6 = 802.11ax (20 MHz only on these chips). None of the chips here supports the 6 GHz band.
USB Serial/JTAG gives you flashing, a serial console and debugging over USB, but the chip can't act as a general USB device (keyboard, MIDI, storage). That needs USB OTG (S2, S3, P4).
Displays: any chip here can drive a small SPI display. The Camera · LCD row lists dedicated parallel or MIPI interfaces.
ESP32-P4: chip revision v3.x runs at 400 MHz; the older v1.3 parts (360 MHz) are being phased out and need different firmware. The P4 has no radio, so Espressif's P4 boards add an ESP32-C6 for Wi-Fi 6 and Bluetooth LE.
Newer parts such as the ESP32-S31 aren't covered here.
Espressif datasheets: ESP8266EX, ESP8285, ESP32, ESP32-S2, ESP32-S3, ESP8684 (ESP32-C2), ESP32-C3, ESP32-C6, ESP32-C61, ESP32-C5, ESP32-H2, ESP32-P4. Also the ESP32-P4 v3.x user guide, P4 v1.3 EOL notice and ESP-IDF TWAI docs for the P4.