Turn a Raspberry Pi Zero W into a Tiny Web Server with SSH and Ngrok

Raspberry Pi (RPi) is a credit‑card‑sized Linux‑based computer; the Zero W model is about one‑third the size of a 3B+ board while still offering a 1 GHz BCM2835 CPU, 512 MB RAM, Wi‑Fi/Bluetooth, micro‑USB power and OTG, mini‑HDMI, GPIO pins, and a micro‑SD slot for the OS.

1. Prepare the SD Card

16 GB or 32 GB SanDisk micro‑SD card

Standard USB‑A to micro‑USB data cable (not Type‑C)

SD card formatter (e.g., SDFormatter)

Win32DiskImager for flashing the image

Raspbian Stretch Lite image (official, no desktop)

Download the raspbian‑stretch‑lite.img (≈1.7 GB) from the Raspberry Pi website, unzip the .zip archive, and locate the .img file.

2. Flash the Image

sudo win32diskimager

Insert the micro‑SD card into a reader, select the .img file in Win32DiskImager, choose the correct device, and click “Write”. After completion, safely eject the card.

3. Enable Headless SSH and Wi‑Fi

After flashing, the card will have a small boot partition (≈40 MB) visible on Windows. Do not remove the card yet.

Create an empty file named ssh (no extension) in the boot partition to enable SSH on first boot.

Create wpa_supplicant.conf in the same partition with the following content (replace with your SSID and password):

country=CN
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="YOUR_WIFI_SSID"
    psk="YOUR_WIFI_PASSWORD"
}

This makes the Zero W connect to your Wi‑Fi automatically, allowing SSH access without a monitor.

4. Boot and Find the IP Address

Insert the card into the Zero W, power it via the micro‑USB cable (5 V 1 A). After a few minutes the LED will become steady. Check your router’s DHCP table to locate the Pi’s IP (e.g., 192.168.0.104).

5. SSH into the Device

Use an SSH client such as PuTTY:

ssh [email protected]
Password: raspberry

Login succeeds, confirming the system is running.

6. System Optimizations

Change APT sources to a domestic mirror (e.g., USTC) for faster downloads:

sudo nano /etc/apt/sources.list
# replace with:
deb http://mirrors.ustc.edu.cn/raspbian/raspbian/raspbian stretch main contrib non-free rpi

sudo nano /etc/apt/sources.list.d/raspi.list
# replace with:
deb http://mirrors.ustc.edu.cn/archive.raspberrypi.org/debian stretch main ui

Update packages: <code>sudo apt-get update sudo apt-get upgrade </code> Set timezone to Shanghai: <code>sudo dpkg-reconfigure tzdata </code> Enable SSH on boot (two methods): Run sudo raspi-config , go to *Interfacing Options → SSH* and enable. Or edit /etc/rc.local and add /etc/init.d/ssh start before the exit 0 line.

7. Install Nginx

sudo apt-get install nginx
sudo /etc/init.d/nginx start   # start
sudo /etc/init.d/nginx restart # restart
sudo /etc/init.d/nginx stop    # stop

Browse to the Pi’s IP (e.g., http://192.168.0.104 ) to see the default Nginx page.

8. Expose the Service via Ngrok (Intranet Penetration)

To make the web service reachable from the public internet, use a tunneling tool such as Ngrok. The author tested three Chinese‑friendly services (ittun, sunny, natapp) and chose the ittun arm binary because it runs on the Zero W. Download the appropriate ngrok_arm binary, configure it with your auth token, and start a tunnel: <code>./ngrok http 80 </code> The tunnel URL (e.g., http://zerow.ittun.com/ ) forwards traffic to the Pi’s Nginx server. The author runs Ngrok inside a screen session so it stays alive after logout. 9. Performance Note After running Nginx and Ngrok together, the Zero W still has about 250 MB free RAM, CPU temperature stays between 37‑39 °C, and the system runs stably for days.