AudioBento

AAC Compressor

Compress AAC files by adjusting bitrate and sample rate. Compare actual sizes and download your audio locally, without uploading it.

Compression Level

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How to compress AAC files

  1. 1

    Select your AAC files

    Choose one or more .aac files from your device. The compressor accepts valid ADTS AAC with one or two channels. Your selected files stay on your device while they are checked.

  2. 2

    Set bitrate and sample rate

    Start at 128 kbps and Source sample rate. Use a lower bitrate to favor smaller files, or choose a lower sample rate for audio that needs less high-frequency detail.

  3. 3

    Compress and download

    Click Compress AAC to encode new AAC files. Compare actual output sizes with the originals. Listen when your browser supports AAC playback, and download one file or a ZIP of multiple results.

AAC compression for music, speech, and sharing

Adjust the encoding settings, keep your original audio, and compare the new file before downloading it.

01

Choose the bitrate for your task

Higher AAC bitrates generally allow more audio detail but can create larger files. Select a target that fits your intended use and compare the actual result instead of assuming a fixed reduction.

  • Choose from four target bitrates: 192, 128, 96, or 64 kbps.
  • Start at 128 kbps to balance size and quality.
  • Audio quality depends on the source, channels, and encoder.

Compression example

192 kbps
128 kbps
96 kbps
64 kbps
02

Make another AAC copy for sharing

Keep your uploaded recording unchanged and create a separate AAC file for a message or project. Reducing the bitrate can help with larger sources, but encoding an already compressed file may add artifacts.

  • Preserve mono or stereo channels without automatic downmixing.
  • Compare actual bytes before deciding which file to keep.
  • Download the valid AAC output even if it is larger.

Compression example

Original AACCompressed AAC
03

Adjust sample rate for speech

Use Source to retain each recording's decoding sample rate. Lower rates remove high-frequency detail and can suit some speech clips. Your bitrate selection stays independent, subject to valid combinations.

  • Choose Source, 48k, 44.1k or 22k (22,050 Hz).
  • Choose a lower rate when your speech recording needs less high-frequency detail.
  • Invalid bitrate and sample-rate combinations are rejected.

Compression example

48,000 Hz
44,100 Hz
22,050 Hz

Lower rates limit high-frequency detail.

04

Compress batches with saved settings

Use the same requested settings for multiple AAC files. Each file receives its own output plan and retains its original upload. Failed processing can be retried without discarding an earlier completed copy.

  • Download a single completed file or a ZIP of results.
  • Keep your previous successful output during a retry.
  • Compare source and result sizes separately for each file.

Compression example

Saved output settings

AAC · 44,100 Hz128 kbps
AAC · 48,000 Hz128 kbps

AAC compression questions

Which AAC files does this compressor accept?
This tool accepts .aac files containing supported mono or stereo ADTS AAC audio. It does not treat M4A, MP4, MP3, ADIF, or LATM files as raw AAC input. Files with invalid frames or unsupported channel configurations are rejected.
How does the AAC compressor work?
The compressor decodes the original AAC file and re-encodes it with your selected bitrate and sample rate. It writes new AAC frames in ADTS format. The target bitrate influences size but does not guarantee a particular number of bytes.
Does AAC compression keep the original quality?
No. AAC is a lossy codec, so compressing an AAC file again can discard more information. Setting a higher bitrate cannot restore details that have already been removed. Keep your original file and compare the encoded output before using it.
Are Quality and Bitrate the same setting?
This tool controls the output with target bitrate, not a separate quality percentage or quality level. The labels beside each bitrate describe typical use cases only. Actual listening quality varies with your source, sample rate, and channels.
What sample rate should I choose?
Source retains each file’s sample rate. The other choices are 48k (48,000 Hz), 44.1k (44,100 Hz) and 22k (22,050 Hz). Some bitrate and sample rate combinations are not supported.
Why can my compressed AAC file be larger?
The original may already use a lower bitrate, or the selected bitrate may exceed what is needed. ADTS framing and encoder behavior also affect file size. The tool compares the real files and allows download even when there are no savings.
What are the batch limits and retry rules?
Desktop supports up to 10 files within 200 MB total; mobile supports 5 files within 100 MB. Output and memory limits apply as well. Failed files can be retried with their saved settings while old successful results remain available.
Are files uploaded, and can I play the output?
AAC processing takes place locally in your browser, without sending the audio file to a conversion server. Raw ADTS AAC is not playable in every browser, but successful files can still be downloaded. Original tags and artwork are not preserved.

Make a smaller AAC sharing copy

Choose bitrate and sample rate, inspect the actual result, and save the AAC file you want to keep.