AAC to text: transcribe .aac audio files free in your browser

How to convert AAC to text online

No conversion step is needed first. AAC is a natively supported upload format here, alongside MP3, WAV, M4A, OGG, and OPUS — you do not have to convert AAC to MP3 before transcribing.

1. Click the upload area in the transcriber above and select your .aac file. The free plan accepts files up to 5 minutes and 20 MB.
2. Leave the language on auto-detect, or pick one of the 40 supported locales if you already know what is spoken.
3. Choose a speed mode. Best accuracy is the right pick for most uploaded files; the faster modes trade a little precision for speed.
4. Start the transcription and wait a few seconds while the Nemotron 3.5 ASR model processes the audio.
5. Copy the finished text to your clipboard or download it as a .txt file, then paste it into notes, documents, or an editor.

What an AAC file actually is

AAC, short for Advanced Audio Coding, is the lossy codec that succeeded MP3. It delivers better quality at the same bitrate, which is why it became the default for a huge range of consumer audio: Android voice recorder apps, Apple Music and iPhone-era audio, YouTube audio streams, and many portable recorders and broadcast tools.

A raw .aac file is usually a bare audio stream saved without a container — common output from Android recording apps. These files play fine but are painful to skim, search, or quote. Turning AAC to text fixes that: a five-minute memo becomes a paragraph you can read in twenty seconds, search by keyword, and paste anywhere.

One honest caveat: DRM-protected iTunes Store files with the .m4p extension cannot be transcribed by this tool or by any other. DRM encrypts the audio stream itself. Music bought from the iTunes Store before it went DRM-free in 2009, and many protected audiobooks, fall into this bucket. Anything you recorded yourself transcribes normally.

.aac vs .m4a: codec versus container

The two are related but not identical. AAC is the codec — the compression method itself. M4A is a container: an MPEG-4 wrapper that usually carries AAC-encoded audio plus metadata such as title and artist. So most .m4a files are AAC inside, and a bare .aac file is the same kind of audio without the wrapper.

For transcription the difference barely matters, because both extensions are accepted uploads. If your recorder produced .m4a — Apple Voice Memos does — upload it as-is, and see the dedicated M4A guide linked below for iPhone-specific details. If it produced .aac, upload that. Either way the same model reads the audio and returns the same clean text.

AAC to text in 40 languages

The transcriber supports 40 language locales: English, Spanish, French, German, Portuguese, Italian, Dutch, Russian, Ukrainian, Polish, Japanese, Korean, Hindi, Arabic, Vietnamese, Thai, Turkish, and more. Chinese means Mandarin, served through the zh-CN locale.

Automatic language detection means you do not have to declare the language up front. The model identifies it from the audio, and it even follows a speaker who switches languages mid-recording — useful for bilingual voice notes and interviews. If detection picks wrong on a short, noisy clip, set the locale manually and run the file again.

Four speed modes, one model

Every mode runs the same NVIDIA Nemotron 3.5 ASR model — a 0.6B-parameter cache-aware FastConformer-RNNT streaming architecture. The chunk size controls how much audio context the model sees at once: bigger chunks mean more context and higher accuracy, at the cost of a slightly longer wait.

Free plan and Pro limits

For occasional AAC files — a voice memo, a lecture snippet, a saved clip — the free tier is usually enough. Pro exists for people who transcribe every day and need more minutes, not for unlocking hidden features.

• Free: 3 transcriptions per day per connection, each file up to 5 minutes and 20 MB. No account, no email, no credit card.
• Pro: $9 per month for 300 audio minutes per month, activated with a Creem license key that works in up to 3 browsers.
• Output is identical on both plans: punctuated, capitalized plain text you can copy to the clipboard or download as a .txt file.

What this AAC transcriber does not do

Also worth knowing: when you record with the built-in microphone option, transcription runs after you stop recording. This is a fast turnaround, not a live caption overlay.

And one disambiguation, since the acronym collides: this page is about the AAC audio format, not Augmentative and Alternative Communication devices used in speech therapy.

• No speaker labels. The output is continuous text; it does not tag who said what.
• No timestamps or subtitle files. There is no word- or segment-level timing, so no SRT or VTT export.
• No video uploads. If your source is a video, extract the audio track first, then upload that.
• No batch mode and no public API. Files are transcribed one at a time in the browser.