ESP32-C61 vs ESP32-C6: Wi-Fi 6 vs Thread/Zigbee

Choose the ESP32-C6 if the project needs Zigbee, Thread, Matter-over-Thread or the more complete smart-home feature set. It combines 2.4 GHz Wi-Fi 6 and BLE with an IEEE 802.15.4 radio, 512 KB HP SRAM and a separate 20 MHz low-power RISC-V processor. Choose the ESP32-C61 when the project only needs Wi-Fi 6 + Bluetooth LE and would benefit from a simpler, potentially lower-cost platform with newer Bluetooth, up to 16 MB flash and 8 MB PSRAM in current WROOM configurations. Despite the name, the C61 is not a more powerful C6: it removes the C6’s 802.15.4 radio and several peripherals in exchange for a more streamlined Wi-Fi/BLE architecture.

Materials You’ll Need

For experimenting with these two chips, the following hardware is useful:

Item	Why you may need it
ESP32-C61-DevKitC-1	Test the C61’s Wi-Fi 6, BLE and PSRAM capabilities
ESP32-C6-DevKitC-1	Test Wi-Fi 6, BLE, Zigbee and Thread
USB-C data cable	Programming and power
Breadboard	Easy prototyping
Dupont jumper wires	Connecting sensors and modules
SHT40, BME280 or another I²C sensor	Simple comparison project
Optional Zigbee/Thread coordinator or border router	Useful when testing the C6’s 802.15.4 radio
Multimeter	Useful for power and GPIO testing

For a basic Home Assistant sensor, only one development board, a USB-C data cable and a sensor are really required.

Affiliate links can be added cleanly to the individual items above without interrupting the technical sections of the article.

ESP32-C61 and ESP32-C6 at a glance

The names make these chips sound as though the C61 is simply a newer C6.

That is misleading.

Both are 160 MHz RISC-V ESP32 chips with 2.4 GHz Wi-Fi 6 and Bluetooth LE, but their design priorities are different.

The C6 is Espressif’s multiprotocol smart-home chip.

The C61 is a streamlined Wi-Fi/BLE IoT chip.

Feature	ESP32-C61	ESP32-C6
Main CPU	RISC-V single-core	RISC-V single-core
Max CPU speed	160 MHz	160 MHz
Separate LP CPU	No	RISC-V up to 20 MHz
Internal SRAM	320 KB	512 KB HP + 16 KB LP
Wi-Fi	Wi-Fi 6	Wi-Fi 6
Wi-Fi frequency	2.4 GHz	2.4 GHz
5 GHz Wi-Fi	No	No
Bluetooth	Bluetooth Core 6.0	Bluetooth 5.3
IEEE 802.15.4	No	Yes
Zigbee	No	Yes, Zigbee 3.0
Thread	No	Yes, Thread 1.3
Matter over Thread	No	Yes
Module flash	Up to 16 MB	Up to 8 MB
Module PSRAM	Up to 8 MB	No on standard C6-WROOM
ADC channels	4	7
USB Serial/JTAG	Yes	Yes
Typical chip deep sleep	~10 µA	~7 µA
Best for	Wi-Fi/BLE IoT	Zigbee/Thread/Matter

The most important distinction is therefore simple:

C61 = Wi-Fi 6 + BLE

C6 = Wi-Fi 6 + BLE + Zigbee/Thread.

First, both chips have Wi-Fi 6

The title of this comparison can easily create the wrong impression.

The C61 does not have Wi-Fi 6 while the C6 lacks it.

Both support:

2.4 GHz Wi-Fi 6 / IEEE 802.11ax

with backwards compatibility for:

• 802.11b
• 802.11g
• 802.11n

Both can reach approximately:

150 Mbps

under appropriate Wi-Fi conditions.

So the decision is not:

Wi-Fi 6
vs
Zigbee

It is more accurately:

Wi-Fi 6 + BLE
vs
Wi-Fi 6 + BLE + Zigbee/Thread

That distinction matters when deciding which chip actually fits the project.

Neither chip has 5 GHz Wi-Fi

Another common source of confusion is the C-series naming.

Neither the C61 nor the C6 supports 5 GHz Wi-Fi.

Both operate in the:

2.4 GHz band

only.

If the requirement is:

2.4 GHz + 5 GHz Wi-Fi 6

the relevant ESP32 is the:

ESP32-C5

not the C61.

This is especially important when comparing online product listings because some sellers loosely use phrases such as “new Wi-Fi 6 ESP32” without making the frequency band clear.

Both use a 160 MHz RISC-V main CPU

Raw application-CPU performance is very similar.

ESP32-C61

32-bit RISC-V
single-core
up to 160 MHz

ESP32-C6

32-bit RISC-V
single-core
up to 160 MHz

C61’s current datasheet gives a CoreMark figure of approximately:

553.78 CoreMark at 160 MHz.

For ordinary embedded workloads such as:

• reading sensors
• MQTT
• Home Assistant
• web APIs
• GPIO
• relays
• BLE

both have plenty of processing power.

A BME280 does not care which one has the more advanced internal architecture.

The real differences begin when memory, low-power processing and radio protocols are considered.

C6 has a second low-power RISC-V CPU

One of the C6’s less obvious advantages is its separate:

20 MHz low-power RISC-V processor.

The main 160 MHz processor can be powered down while the LP processor handles suitable low-complexity tasks.

Conceptually:

160 MHz main CPU
        ↓
      sleeps

20 MHz LP CPU
        ↓
monitors selected events
        ↓
wakes main processor

This can be valuable for:

• sensor threshold monitoring
• low-power event detection
• periodic background tasks
• battery devices

The C61 does not have an equivalent separate programmable LP RISC-V core.

So despite being the newer-looking part number, C61 actually has the simpler processor architecture.

C6 has significantly more internal SRAM

This is another major difference.

ESP32-C61

Provides:

320 KB SRAM
32 KB L1 cache

ESP32-C6

Provides:

512 KB HP SRAM
16 KB LP SRAM

The C6 therefore has considerably more internal working memory.

That can matter for:

• networking
• TLS
• ESPHome
• Zigbee
• Thread
• Matter
• large JSON documents
• multiple tasks
• protocol gateways

If the application stays entirely inside internal memory, the C6 has the stronger architecture.

But C61 has much better external-memory options

This is where the C61 becomes interesting.

Current ESP32-C61-WROOM-1 modules support configurations with up to:

16 MB flash
8 MB PSRAM

The standard ESP32-C6-WROOM-1 family provides up to:

8 MB flash

and does not provide PSRAM in the same way.

So the memory comparison is not simply:

C6 has more memory.

It is:

C6 has more internal SRAM.

C61 can have far more total memory through PSRAM.

That makes C61 surprisingly attractive for some Wi-Fi applications involving:

• large buffers
• web interfaces
• large JSON objects
• data logging
• caching
• audio buffers
• bigger ESPHome configurations

The current C61 DevKit has PSRAM

The official ESP32-C61-DevKitC-1 v2.0 is built around ESP32-C61-WROOM-1.

Espressif’s current board documentation describes configurations providing up to:

8 MB SPI flash

and:

2 MB PSRAM.

That already gives the C61 development board an interesting advantage for projects that benefit from external RAM.

The wider C61-WROOM module family can go beyond that, with configurations reaching up to 16 MB flash and 8 MB PSRAM.

C6 has the critical 802.15.4 radio

This is the main reason the C6 exists in so many smart-home projects.

ESP32-C6 contains a native:

IEEE 802.15.4 radio

operating at 2.4 GHz.

That hardware enables:

• Zigbee
• Thread
• Matter over Thread

The C61 does not contain an 802.15.4 radio.

This is not something that can be added with firmware.

If a C61 project later needs Thread or Zigbee, it will require a separate external radio.

With C6, the radio is already built into the chip.

C6 supports Zigbee 3.0

ESP32-C6 supports:

Zigbee 3.0

using its integrated 802.15.4 hardware.

That makes it useful for projects such as:

• Zigbee temperature sensors
• Zigbee relays
• smart switches
• door sensors
• motion sensors
• lighting controllers
• Zigbee routers
• gateways

For someone building a modern Home Assistant Zigbee project, choosing C6 over C61 is straightforward.

C61 cannot act as a native Zigbee radio.

C6 supports Thread 1.3

ESP32-C6 also supports:

Thread 1.3.

That is particularly relevant for Matter devices.

Thread provides an IP-based low-power mesh network and is increasingly used for:

• smart plugs
• environmental sensors
• switches
• thermostats
• Matter accessories

Again, the C61 lacks the required radio.

If the project requirement contains the word:

Thread

choose:

C6.

Matter over Wi-Fi is different

The absence of 802.15.4 does not mean C61 is useless for Matter.

Matter can also run over Wi-Fi.

Conceptually:

C61
→ Matter over Wi-Fi

may be possible with an appropriate software stack.

But:

C61
→ Matter over Thread

is impossible without another radio.

The C6 is therefore the more flexible Matter platform because its hardware can support both Wi-Fi networking and Thread networking.

C61 has newer Bluetooth hardware

C61 gets an advantage on the BLE side.

Current Espressif documentation lists it as:

Bluetooth Core 6.0 certified.

Its BLE functionality includes features such as:

• LE Power Control
• Direction Finding
• AoA/AoD
• PAwR
• LE Connection Subrating
• extended advertising
• Bluetooth Mesh 1.1

The C6 WROOM family is currently documented as:

Bluetooth 5.3 certified.

For a conventional BLE sensor, this distinction may not matter.

For newer BLE applications or products with a longer commercial lifespan, the C61’s newer Bluetooth implementation is appealing.

Neither supports Bluetooth Classic

Both chips provide:

Bluetooth Low Energy only.

Neither provides legacy Bluetooth Classic.

So projects requiring older Bluetooth Classic profiles should not choose either chip solely because it says “Bluetooth.”

For:

• BLE sensors
• beacons
• provisioning
• BLE Mesh
• Home Assistant BLE integrations

both are appropriate.

C61 is deliberately more streamlined

The C61 does not merely remove the 802.15.4 radio.

Its peripheral set is also simpler.

It retains useful interfaces such as:

• UART
• SPI
• I²C
• I²S
• USB Serial/JTAG
• LED PWM
• ADC
• temperature sensor
• SDIO slave
• analog comparator

But the C6 contains a richer peripheral set including functionality such as:

• pulse counter
• RMT
• motor-control PWM
• TWAI
• parallel I/O
• low-power peripherals

depending on the specific function being used.

For a simple connected sensor, this difference may be irrelevant.

For a sophisticated controller, the C6 provides more hardware flexibility.

C61 has fewer ADC inputs

C61’s current chip specification provides a:

12-bit ADC with up to four channels.

ESPHome currently maps those to:

GPIO1
GPIO3
GPIO4
GPIO5

C6 provides:

seven ADC channels

on:

GPIO0–GPIO6

So if several analog sensors are required:

C6 is more convenient.

For most modern digital environmental sensors using I²C, this difference is much less important.

GPIO availability is broadly similar

The bare C61 supports up to:

30 programmable GPIOs.

C61-WROOM modules expose up to:

23 GPIOs.

The C6 chip is available in configurations with 30 or 22 GPIOs, while the common C6-WROOM module exposes:

23 GPIOs.

So neither chip has a major practical GPIO advantage at WROOM-module level.

The actual development board layout matters more.

Both have native USB Serial/JTAG

Both C61 and C6 include:

USB Serial/JTAG.

This is useful for:

• flashing firmware
• serial debugging
• JTAG debugging

without necessarily requiring an external USB-to-UART converter.

It should not be confused with the more capable general-purpose USB OTG functionality found on chips such as ESP32-S3.

For typical development-board programming, however, USB Serial/JTAG is extremely convenient.

Deep-sleep current surprisingly favours C6

Because C61 is positioned as a streamlined IoT chip, it would be reasonable to assume it always uses less power.

The current headline chip figures do not support that assumption.

Espressif specifies approximately:

ESP32-C61
Deep sleep ≈ 10 µA

while C6 is approximately:

ESP32-C6
Deep sleep ≈ 7 µA

under the relevant datasheet conditions.

The difference is small, but interesting.

For a sensor sleeping almost all the time, the older C6 can actually have the theoretical advantage.

Board-level power matters far more

A difference of:

3 µA

at chip level means very little if the development board contains:

• a power LED
• an inefficient regulator
• USB circuitry
• voltage dividers
• external PSRAM

consuming hundreds of microamps or several milliamps.

For serious battery design:

measure the complete board.

Do not select C61 or C6 purely from one datasheet sleep-current number.

Why would C61 exist if C6 has more features?

Because not every product needs Zigbee and Thread.

Suppose a commercial product only needs:

Wi-Fi
+
BLE commissioning

Including an 802.15.4 radio that will never be used adds unnecessary silicon complexity.

C61 focuses on the enormous market for ordinary Wi-Fi/BLE products such as:

• smart plugs
• appliances
• sensor hubs
• data loggers
• consumer electronics
• POS devices
• industrial telemetry

It also offers strong external-memory configurations.

That makes it a practical cost-focused option rather than a replacement for the C6.

Think of C61 as a different branch, not C6.1

The name C61 is unfortunately easy to interpret as:

C6.1

or:

upgraded C6

That is not a useful way to think about it.

The architecture is closer to:

ESP32-C6

Wi-Fi 6
BLE
802.15.4
Thread
Zigbee
LP CPU
larger internal SRAM

ESP32-C61

Wi-Fi 6
newer BLE
simpler system
PSRAM options
larger flash options

The C61 is therefore more specialized, not universally better.

Which is better for ESPHome?

In 2026, ESPHome supports both:

variant: esp32c6

and:

variant: esp32c61

The current ESPHome platform documentation explicitly describes the C61 as a lower-cost C6-family option without the 802.15.4 radio. ESPHome also added C61 PSRAM support in the 2026.4 release.

For something simple such as:

SHT40
+
Wi-Fi
+
Home Assistant

either is capable.

C61 becomes interesting if:

• PSRAM helps
• newer BLE matters
• Zigbee/Thread will never be required

C6 remains more flexible for smart-home experimentation.

Which is easier with Arduino IDE?

Today:

ESP32-C6 is easier.

The normal Arduino-ESP32 documentation lists C6 as a fully stable supported target.

C61 is supported, but Espressif currently notes that it requires either:

• using Arduino as an ESP-IDF component, or
• rebuilding the Arduino static libraries

rather than the same straightforward precompiled-board workflow used by fully supported targets.

This is an important practical difference.

For someone whose entire workflow is:

Arduino IDE
→ choose board
→ compile
→ upload

C6 is currently the safer choice.

C61 software support is catching up quickly

The situation is improving rapidly.

ESP-IDF already has dedicated C61 support, current ESPHome recognizes the C61 platform, and PSRAM support has been added.

So C61 should not be regarded as unsupported hardware.

It is simply less mature in the standard Arduino workflow than C6 at the moment.

For ESP-IDF users, this disadvantage is much smaller.

Which is better for Home Assistant?

For a normal Wi-Fi Home Assistant sensor:

Either.

For example:

ESP32
+
SHT45
+
ESPHome
+
Home Assistant

does not need an IEEE 802.15.4 radio.

If a C61 board is cheaper and well supported by the firmware being used, it can make perfect sense.

But for someone buying one board to experiment with:

• Wi-Fi
• BLE
• Zigbee
• Thread
• Matter

the C6 clearly gives more possibilities.

Which is better for Zigbee?

This one is easy.

ESP32-C61

No native Zigbee

ESP32-C6

Zigbee 3.0

Winner:

ESP32-C6

Which is better for Thread?

Again:

ESP32-C61

No 802.15.4 radio.

ESP32-C6

Thread 1.3.

Winner:

ESP32-C6

Which is better for Matter?

For:

Matter over Thread

choose:

C6

For:

Matter over Wi-Fi

C61 can be interesting, especially where PSRAM and larger flash are useful, assuming the chosen framework supports the intended configuration.

For maximum flexibility:

C6 remains the safer Matter-development board.

Which is better for BLE projects?

This is closer.

For ordinary BLE sensors:

Either

For more recent BLE features:

C61

has the more modern Bluetooth Core 6.0 implementation.

For BLE combined with Zigbee or Thread:

C6

wins because the required 802.15.4 radio is also present.

Which is better for a web server?

Potentially:

C61

despite its lower internal SRAM.

Why?

Because C61 WROOM modules can provide:

up to 16 MB flash
+
up to 8 MB PSRAM

That gives large applications far more external memory for:

• HTML
• buffers
• JSON
• cached data
• file systems

For a modest configuration page, either chip is fine.

Which is better for a battery sensor?

For a very basic sleep-heavy node:

C6 has the better published chip deep-sleep figure.

But C61 may still be competitive in a real product depending on:

• board regulator
• wake duration
• Wi-Fi connection time
• peripheral current
• sensor design

The final answer should be based on measuring the actual hardware.

Which is better for a simple Wi-Fi relay?

Probably:

C61

if it costs less and the development environment supports it conveniently.

A relay does not need:

• Zigbee
• Thread
• 512 KB SRAM
• LP CPU
• seven ADC inputs

The C61 is exactly the sort of chip that makes sense when unnecessary functionality can be removed.

Which is better for a smart-home gateway?

C6

A gateway may benefit from simultaneously supporting:

Wi-Fi
+
BLE
+
Zigbee
+
Thread

That combination is the C6’s main strength.

C61 would require an external 802.15.4 radio to provide equivalent Zigbee/Thread capability.

Which is better for a basic Wi-Fi sensor?

This depends largely on price.

If the project is:

Temperature
Humidity
Wi-Fi
MQTT

both chips are excessive in terms of processing capability.

C61 may be attractive as the lower-cost option.

C6 becomes worthwhile if the possibility of migrating the product to Zigbee/Thread later has value.

C61 vs C6 by project

Project	Better choice
Basic Wi-Fi sensor	C61
Wi-Fi relay	C61
BLE sensor	C61 / C6
Advanced BLE project	C61
Large Wi-Fi app with PSRAM	C61
Large flash requirement	C61
Zigbee sensor	C6
Zigbee router	C6
Thread sensor	C6
Matter over Thread	C6
Smart-home gateway	C6
Many analog inputs	C6
Rich embedded peripherals	C6
Simplest Arduino workflow	C6
ESPHome Wi-Fi node	Either
Maximum protocol flexibility	C6

Why C6 remains the better all-rounder

C61 has several interesting advantages, particularly:

• newer BLE
• PSRAM
• larger flash options
• potentially lower product cost

But C6 remains the more versatile microcontroller.

It provides:

• more internal SRAM
• low-power processor
• Zigbee
• Thread
• Matter-over-Thread capability
• more ADC channels
• richer peripherals
• mature Arduino support
• slightly lower specified deep-sleep current

So when the future project requirements are unknown:

C6 remains easier to recommend.

Why C61 is still important

The C61 solves a different problem.

There are millions of embedded devices that will never need:

Zigbee
Thread
Matter-over-Thread

but may benefit from:

Wi-Fi 6
BLE
large flash
PSRAM
lower cost

For those products, C61 can be the more efficient engineering choice.

It avoids paying for capabilities that will never be used.

The simplest buying decision

Ask one question first:

Could this project need Zigbee or Thread?

If:

Yes → ESP32-C6

If:

No → continue

Then ask:

Do large flash or PSRAM matter?

If:

Yes → ESP32-C61 becomes very interesting

If:

No → choose whichever board is cheaper, easier to obtain and better supported by the chosen framework.

For Arduino IDE beginners today, C6 still has the smoother software path.

Related ESP32 Guides

These articles are natural internal links from this comparison:

• ESP32-C5 vs ESP32-C6: Which Should You Buy?
• ESP32-C3 vs ESP32-C6: Which One Should You Use?
• ESP32-C6 DevKitC vs DevKitM: Which C6 Board Should You Buy?
• ESP32-C6 SuperMini Pinout + Safe GPIOs
• Full Comparison of All ESP32-C Versions and Development Boards
• Best ESP32 for Matter, Thread & Zigbee
• ESP32-H2 vs ESP32-H21 vs ESP32-H4

These should be linked internally in the published article to keep readers moving through the esp32.co.uk C-series and smart-home clusters.

Final recommendation

The ESP32-C61 is not a replacement for the ESP32-C6.

It is better thought of as a more streamlined alternative.

Choose ESP32-C61 for:

Wi-Fi 6
+
Bluetooth LE
+
large flash / PSRAM options

when Zigbee and Thread are unnecessary.

Choose ESP32-C6 for:

Wi-Fi 6
+
Bluetooth LE
+
Zigbee
+
Thread
+
Matter-over-Thread

and when the richer low-power and peripheral architecture is useful.

For a cheap Wi-Fi sensor:

C61 can be the smarter choice.

For a smart-home development board:

C6 wins easily.

And for someone buying just one of them with no fixed project yet:

Buy the ESP32-C6.

It gives up the C61’s large PSRAM/flash options, but its combination of Wi-Fi 6, BLE, Zigbee and Thread gives far more directions for future projects.

Official Datasheets & External Resources

All manufacturer and software documentation is collected here so the article body remains focused and does not repeatedly send readers away from esp32.co.uk.

Espressif ESP32-C61 Series Datasheet — official CPU, SRAM, Bluetooth, GPIO, ADC and power specifications. (Espressif Documentation)

Espressif ESP32-C61-WROOM-1 / WROOM-1U Datasheet — flash, PSRAM, module GPIO and antenna configurations. (Espressif Documentation)

Espressif ESP32-C61-DevKitC-1 v2.0 User Guide — official development-board configuration and module details. (Espressif Systems)

Espressif ESP32-C6 Series Datasheet — Wi-Fi 6, BLE, Zigbee, Thread, memory, ADC and power specifications. (Espressif Documentation)

Espressif ESP32-C6-WROOM-1 / WROOM-1U Datasheet — official C6 module specifications. (Espressif Documentation)

Arduino-ESP32 Supported SoCs — current C6 and C61 Arduino support status. (Espressif Systems)

ESPHome ESP32 Platform Documentation — current ESP32-C61 and ESP32-C6 platform support. (ESPHome – Smart Home Made Simple)