WeakSim - Weak Network Sim

Weak network simulator

Only for iPhone

Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.

iPhone

WeakSim is an iOS weak network simulator. It intercepts device traffic through the system VPN (Packet Tunnel), applying delays, packet loss, bandwidth throttling and other impairments to TCP/UDP packets locally. It reproduces real-world weak network scenarios such as subways, elevators, high-speed trains, and poor signal areas, helping you verify your app's timeout, reconnection, and degradation logic. Core Features: - System-level traffic interception: Based on Network Extension Packet Tunnel, all device traffic goes through weak network simulation. - 9 built-in preset scenarios: 2G / 3G / Weak 4G / Weak Wi-Fi, Subway, Elevator, High Latency, High-Speed Train Disconnection, DNS Timeout. - Customizable network impairment parameters: Latency & Jitter, Packet Loss, Up/Down Bandwidth Throttling, Reordering, Duplication, Tampering, Periodic Disconnection, DNS Failure / Timeout / Error / Domain Hijacking. - Multiple network impairment models: Latency supports Uniform / Gaussian / Long-tail distribution; Packet Loss supports Random / Burst mode, closer to real link fluctuation. Sensitive Data: - WeakSim does not capture network packets; it only applies impairments such as latency, packet loss, and bandwidth throttling to network packets. - WeakSim collects metrics such as the number of uplink and downlink packets, traffic volume, and packet loss count, and stores them locally using SQLite without involving any remote servers. 【Auto-Renewable Subscription】 1. Subscription Service: a) Pro Weekly - Weekly auto-renewing subscription (1 week) 2. Payment: Payment will be charged to your iTunes Account upon confirmation of purchase. 3. Auto-Renewal: Your iTunes account will be charged within 24 hours before the current period ends. Once the charge succeeds, the subscription period will be extended by one term. 4. Cancellation: You can manage or cancel your subscription by going to iPhone Settings → [Your Name] → iTunes & App Store → Apple ID → View Apple ID → Account Settings → Subscriptions. To avoid being charged, cancel at least 24 hours before the end of the current billing cycle. 5. Terms of Service: https://xling-net.github.io/weaksim/terms-of-service.html 6. Privacy Policy: https://xling-net.github.io/weaksim/privacy-policy.html

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The developer, Nanning Signalling Network Technology Co., Ltd, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Seller
    • Nanning Signalling Network Technology Co., Ltd
    Size
    • 15.8 MB
    Category
    • Developer Tools
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English and Simplified Chinese
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    • © 2026 Nanning Signalling Network Technology Co., Ltd