Free Audio to Text Converter:
MP3, WAV & M4A to Text

What the Audio to Text Converter Does

How to Convert Audio to Text

Converting an audio file to text takes three steps. The entire process is automatic — no manual transcription, no timestamps to set by hand, and no software to install.

How AI Audio-to-Text Works

Our audio to text converter is powered by OpenAI Whisper, one of the most capable speech recognition models available. Understanding how it works explains why it produces accurate transcriptions across so many languages and audio conditions.

Whisper uses an encoder-decoder transformer architecture — the same fundamental design behind modern large language models, adapted specifically for speech. Here is what happens when you upload an audio file:

• Audio preprocessing. The raw audio waveform is converted into a log-mel spectrogram — a visual representation of the audio's frequency content over time. This transforms the one-dimensional audio signal into a two-dimensional image-like input that the neural network can process. The spectrogram is divided into 30-second chunks for processing.
• Encoder. The spectrogram passes through the encoder — a stack of transformer layers that analyze the frequency patterns and build a rich internal representation of what was spoken. The encoder learns to recognize phonemes, word boundaries, intonation, and language-specific patterns. Each layer refines the representation, capturing everything from individual sounds to longer prosodic structures.
• Decoder. The decoder takes the encoder's representation and generates text one token at a time, predicting the next word based on both the audio context and the text generated so far. This autoregressive process is what enables Whisper to produce coherent, properly punctuated sentences rather than just isolated word predictions. The decoder handles capitalization, punctuation, and formatting automatically.
• Multitask training. Whisper was not trained only on transcription. It was trained on multiple tasks simultaneously: transcription, translation, language identification, and timestamp prediction. This multitask approach on 680,000 hours of multilingual audio data collected from the internet gives the model robust generalization — it handles accents, background noise, varied recording quality, and domain-specific vocabulary far better than models trained on clean studio recordings alone.

The result is a model that behaves less like a narrow speech-to-text engine and more like a system that genuinely understands spoken language. It knows when a pause is a comma versus a period, when a speaker is asking a question, and how to spell domain-specific terms it encountered during training.

Output Formats

The audio to text converter produces three output formats. Each serves a different purpose, so choosing the right one depends on what you plan to do with the transcription.

When to use which: If you just need the words — for a document, email, or notes — choose TXT. If you are adding subtitles to a video for YouTube, social media, or a video editor, choose SRT. If you are embedding subtitles in a web page using HTML5 <video> with a <track> element, choose VTT. When in doubt, SRT is the safest choice — virtually every video tool and platform supports it. For the full captioning workflow, see how to make SRT and VTT subtitles from a video.

Language Support

The language menu lists 15 languages plus Auto-detect. With Auto-detect, the model identifies the spoken language from the first 30 seconds of audio and transcribes the file in that language. If the guess is wrong, select the language manually.

These are the 15 languages you can select:

Whisper was trained on audio in 99 languages, so Auto-detect can also recognize languages that are not in the menu, such as Hindi, Vietnamese or Greek. Those languages are not in our menu, and results are usually weaker for languages with less training data. The model detects the language from the speech itself, not from file metadata.

Audio to Text vs Manual Transcription

Before AI transcription tools existed, converting audio to text meant either typing it yourself or hiring a professional transcriptionist. Here is how the two approaches compare:

For most use cases — meeting notes, lecture transcripts, podcast show notes, voice memo archives — AI transcription is the clear winner. It is free, done in minutes, and the remaining errors are quick to fix. Manual transcription still has an edge for legal depositions, medical records, and situations where 100% accuracy is legally required, since a human can use context and domain expertise to resolve ambiguities that the AI might miss.

The practical approach for demanding use cases: use AI to generate the first draft in minutes, then have a human review and correct the handful of errors. This hybrid workflow saves most of the typing while keeping a human check on accuracy. For a worked example of that review step, see how to transcribe an interview quickly with AI.

What the TXT, SRT and VTT Files Look Like

Here are the same two sentences in each output format, laid out the way the converter writes them:

TXT

Welcome to the show.
Today we talk about home recording.

SRT

1
00:00:00,000 --> 00:00:02,480
Welcome to the show.

2
00:00:02,480 --> 00:00:05,120
Today we talk about home recording.

VTT

WEBVTT

00:00:00.000 --> 00:00:02.480
Welcome to the show.

00:00:02.480 --> 00:00:05.120
Today we talk about home recording.

TXT puts each recognized segment on its own line, with no times. SRT numbers every cue and uses a comma before the milliseconds. VTT starts with a WEBVTT header and uses a period.