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title: Troubleshooting
description: Resolve common issues when uploading pre-recorded audio to Pulse STT
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# Troubleshooting pre-recorded uploads

Go through this guide to learn about common bugs and issues that might occur when transcribing audio with Pulse STT.

## Low-quality transcripts

**Symptoms:** transcripts miss words or contain heavy noise.

**Fixes:**

* Resample audio to at least 16 kHz and keep it mono.
* Prefer lossless codecs (WAV, FLAC) whenever you control the capture pipeline.
* Maintain 128 kbps or higher bitrate for compressed formats.
* Normalize and denoise audio before uploading (see [best practices](/waves/documentation/speech-to-text/pre-recorded/best-practices)).

## Large file sizes

**Symptoms:** uploads stall or take too long to complete.

**Fixes:**

* Use compressed formats such as MP3 or OGG if WAV is oversized.
* Downsample anything above 16 kHz; speech rarely needs more.
* Split recordings longer than 10 minutes into smaller chunks.
* Keep bitrates near 128 kbps unless fidelity is critical.

## Unsupported format errors

**Symptoms:** API responses return format/codec errors immediately.

**Fixes:**

* Convert the file with FFmpeg to a supported format (WAV, MP3, FLAC, OGG, WebM).
* Make sure the file extension matches the actual codec/container.
* Validate codec compatibility—Linear PCM is the safest fallback.

## Still stuck?

* Re-run uploads with `?word_timestamps=true` to confirm the request reaches the model.
* Capture the failing `request_id` and reach out to us:
  * Email: [support@smallest.ai](mailto:support@smallest.ai)
  * Discord: [Join our community](https://discord.gg/5evETqguJs)