1. Install STT4U
Open the STT4U page on the Microsoft Store and install the app. It’s free.
The app follows your Windows display language (English or Japanese). You can change it with the Language box at the top right of the setup screen, or at the top of Settings.
2. Set up OpenRouter
What is OpenRouter?
OpenRouter is a service that lets you use AI models from many companies with one account and one balance. STT4U uses these models for speech recognition and text cleanup.
You pay OpenRouter directly for the AI you use. STT4U itself is free. Costs are deducted from credits you prepay on OpenRouter. You can use the same account and key with other apps that work with OpenRouter.
As a rough guide, the recommended settings cost about $0.005 per minute of speech. That’s about $1.50 a month if you speak for 10 minutes a day, and about $9 a month if you speak for an hour every day. Months you don’t use it cost nothing.
2-1. Create an account
- Go to openrouter.ai
- Select Sign in at the top rightSign in with a Google or GitHub account. You don’t need a new password.
2-2. Add credits
- Open Credits
- Select Add Credits, enter an amount, and prepay by cardSee the table below for how much to add.
| Amount | Good for |
|---|---|
| $5 | Trying it out. For voice typing, this lasts for months, but the fee is relatively high (16%) |
| $10 | People who also use OpenRouter in other apps. With $10 or more in total purchases, you can use free models more often (STT4U has no free speech recognition models) |
| $15 or more | The fee drops to the standard rate (5.5%). A good choice if you add credits in bulk |
2-3. Create an API key
- Open Keys
- Select Create Key
- Enter
STT4Uas the name, and then select CreateIf you create a separate key for each app, OpenRouter shows you how much each app uses. - Copy the string that starts with
sk-or-v1-…
This string is shown only once. If you close it, delete that key and create a new one.
Treat your API key like a password. Don’t show it to or share it with anyone.
3. Paste your API key into STT4U
When you first start STT4U, the setup screen opens.
- Paste the key under “Set your OpenRouter API key”
- Select Save
- Select Get started at the bottom
To add the key later, go to the Models / API screen. To open the setup screen again, go to Settings and select Open setup.
4. Try it
- Click where you want to type, for example in Notepad
- Hold down the Right Ctrl key while you speak
- Release the keyAfter a few seconds, the cleaned-up text is pasted.
You can also start recording by clicking the small floating icon at the bottom of the screen (click it again to stop). Right-click the icon for a menu where you can switch how text is cleaned up or paste the last text again.
You can change the shortcut in Settings, and choose between “Hold to record” and “Press to start, press again to finish.”
STT4U cleans up each dictation in the language you spoke. If you speak both English and Japanese, set Spoken language to “Not specified” on the Models / API screen.
5. Microphone
The Microsoft Store version uses the microphone selected in Windows. To change it, go to Windows Settings > System > Sound, and choose a device under Input. In STT4U, select Open Sound settings in Settings to go straight there.
If Windows asks whether to allow microphone access the first time you record, select Yes.
6. Troubleshooting
- “Your API key wasn’t accepted”: The key was pasted incorrectly or has been deleted. Create a new key and paste it again
- “You don’t have enough credits”: Add credits under Credits on OpenRouter
- Nothing is pasted: Use Troubleshooting at the bottom of the Home screen in STT4U to check the connection, key, and models
- To see how much you’ve used, check the Cost screen in STT4U or Activity on OpenRouter
If that doesn’t help, let us know.
Where your data goes
Your recorded voice and transcribed text are sent through OpenRouter to the servers of the provider running the model. The provider isn’t necessarily the company that created the model. The same model may run at several companies or locations (such as the US or the EU), so a model made by a Chinese company isn’t necessarily processed on servers in China.
OpenRouter itself doesn’t store the content (unless you turn on logging yourself). In OpenRouter’s privacy settings, you can choose options such as avoiding providers that use data for training, or using only providers that don’t store data. For details, see the privacy policy.