# Audio Injection Manual Testing on Real Device Browsers

> For the full site index for AI agents, see [llms.txt](https://www.testmuai.com/support/docs/llms.txt).

**Audio Injection** lets you simulate microphone input on real Android and iOS device browsers during a manual **Real Time** browser session. Use it to test speech-to-text web apps, voice search on the mobile web, browser-based voice assistants, web-based KYC voice verification, and any other microphone-dependent web feature, without speaking into a physical mic.

With TestMu AI Real Time browser testing, you can either inject a **pre-uploaded audio file** or stream **Live Input** directly from your system microphone into the device browser.

**Plus Plan Feature**
This feature is available exclusively with the **Real Device Plus Live** Plan.

To unlock this feature, purchase or upgrade to the required [plan](https://www.testmuai.com/pricing/). If you need assistance, please contact your TestMu AI support representative, reach out to our **[24×7 Chat Support]**, or email us at **support@testmuai.com**.

## Use Cases

- **Web voice search**: Validate browser-based voice search and dictation flows.
- **Speech-to-text web apps**: Confirm transcription accuracy on the mobile web.
- **Web-based KYC**: Test identity flows that record a voice sample in the browser.
- **WebRTC and conferencing**: Verify mic capture in browser conferencing tools.
- **Live exploratory testing**: Use Live Input to drive ad-hoc voice interactions on web pages in real time.

## Supported Devices

**Audio Injection is supported on selected Real Devices only. It is not available on Emulators or Simulators.**

### Android

| Android Device | Android Version |
|---|---|
| Galaxy S26 | 16 |
| Galaxy S24 | 14 |
| Galaxy S23 | 14 |
| Pixel 10 | 16 |
| Pixel 10 Pro | 16 |
| Pixel 10 Pro XL | 16 |
| Pixel 9 | 15 |
| Pixel 8 | 14, 16 |

### iOS

| iOS Device | iOS Version |
|---|---|
| iPhone 17 Pro | 26 |
| iPhone 17 | 26 |
| iPhone 16 | 18 |
| iPhone 15 | 17 |

## Supported File Formats

| Format | Max Size |
|---|---|
| MP3 | 200 MB |
| WAV | 200 MB |

Files are uploaded one at a time and injected one at a time per session.

## Manual Audio Injection Workflow in Browser Testing

### Step 1: Enable Audio Injection in Advanced Settings

1. Go to the TestMu AI **Dashboard** and open **Real Device Browser Testing**.
2. Click **Advanced Settings** on top.
3. Toggle **Enable Audio Injection** on.

Once enabled, the device list is filtered to show **only the devices that support Audio Injection** for the respective OS.

### Step 2: Select a Device and Start Your Session

1. From the filtered device list, pick a supported Android or iOS real device along with the browser you want to test on.
2. Click **Start** to launch the session.

### Step 3: Open Media Injection

1. Inside the live browser session, locate **Media Injection** in the in-session toolbar.
2. Click to open the Media Injection panel.
3. Switch to the **Audio** tab.

You will see two options:

- **Select Files**: inject a pre-recorded audio file
- **Inject Live Input**: stream audio from your system microphone in real time

### Step 4a: Inject an Audio File

Use this mode when you want a deterministic, repeatable input, for example, the same voice query run across many device-browser combinations.

1. In the **Audio** tab, select **Select Files**.
2. Click **Upload** and choose an `.mp3` or `.wav` file (up to **200 MB**, one file at a time).
3. Once uploaded, the file appears in your audio library (latest 5 uploaded).
4. In the browser, navigate to the page that captures microphone input (e.g., tap a voice search icon or **Start Recording**).
5. Grant the page mic permission when prompted.
6. Select the uploaded file and click **Inject**.
7. Once a file is injected, the controls are limited to **Play** and **Pause**. Clicking **Play** streams the audio into the device's microphone pipeline as live mic input, and the browser captures it as if the user were speaking.
8. To switch audio, select a different file and click **Inject** on it. Only **one file can be injected at a time**, and the new file replaces the previously injected one.

Inject and start playback **after** the page has opened the mic. Some recognizers need 1–2 seconds of silence to initialize before they accept speech.

### Step 4b: Use Live Input

Use this mode when you want to drive the device microphone interactively, for example, having an unscripted conversation with a web voice assistant or testing custom prompts on the fly.

1. In the **Audio** tab, select **Inject Live Input**.
2. Grant microphone access to your browser when prompted.
3. In the device browser, open the page that captures microphone input.
4. Click **Start**. Your system microphone is now streamed directly into the device's mic.
5. Speak into your mic. The web page receives your voice in real time.
6. Click **Stop** to end the live stream.

Live Input streams from the same browser tab running the Real Time session. Avoid muting your system mic or switching tabs mid-session. The stream will be interrupted.

## Execution Rules

- The web page must be granted microphone permission. Audio Injection does **not** bypass permission prompts.
- Only one audio source is active at a time. Switching from **Files** to **Live Input** (or vice versa) replaces the previous source.
- For files, only one file can be injected and played at a time.
- The last injected audio is the active source until you stop it or inject another.

## Tips and Best Practices

- Keep audio files short (under 5 minutes) for predictable timing.
- Use 16 kHz mono MP3 or WAV for the most consistent results across Android and iOS browsers.
- For voice-recognition pages, allow the device 1–2 seconds of silence before injecting speech.
- Use **Files** for repeatable regression runs across device-browser pairs; use **Live Input** for exploratory and conversational testing.

## Related Resources

- [Audio Injection Manual Testing (App)](/docs/audio-injection-manual/): Same feature on App Live
- [Audio Injection on Real Devices (Automation)](/docs/audio-injection/): Inject audio via Appium / Selenium tests
- [Browser Testing on Real Devices](/docs/browser-testing-on-real-devices/)

> **Need help?** Reach out via **24×7 chat support** or email **support@testmuai.com**.