Compress Audio to 1MB

Compress audio to 1MB is an automatic audio compression tool that reduces any audio file to under 1 megabyte (1,048,576 bytes) by iterating through sample rates until the output fits the target. Unlike manual bitrate selectors, this tool automatically finds the highest quality sample ratethat still produces an output under 1 MB — so you always get the best possible quality within the size constraint. The tool uses the browser's Web Audio API to decode and resample the audio entirely in your browser — your audio never leaves your device.

1. 1Upload your audio file: Drag and drop or click to select any audio file — MP3, WAV, M4A, AAC, OGG, FLAC, or OPUS. The tool shows the file name and size before compression begins. All processing happens locally in your browser — your audio never leaves your device.
2. 2Automatic sample rate iteration:Click "Compress to 1MB" and the tool tries sample rates from 44.1 kHz down to 8 kHz, estimating the output size at each rate. It selects the highest sample rate that produces an output under 1 MB. If no sample rate achieves the target, the audio is truncated to fit.
3. 3Download the compressed audio:The results panel shows original size, compressed size, reduction percentage, duration preserved, and the compression steps tried. Click "Download Compressed Audio" to save the output as a WAV file.

• Sample rate reduction: The primary compression lever — the tool tries 44.1 kHz, 32 kHz, 22.05 kHz, 16 kHz, 11.025 kHz, and 8 kHz in order, selecting the highest rate that fits under 1 MB. Lower sample rates remove high-frequency content above half the sample rate.
• Audio duration preserved: The tool preserves the full audio duration whenever possible. Only if no sample rate achieves the 1 MB target is the audio truncated — and even then, the maximum possible duration is preserved.
• Bit depth standardization: The output is encoded as 16-bit PCM WAV — the CD standard — which provides 96 dB of dynamic range, more than sufficient for all practical audio use cases.
• Transparent step display: The results panel shows every sample rate tried with green checkmarks (fits under 1 MB) and red X marks (too large), so you can see exactly how the compression was achieved.

For very long audio files at high sample rates, even 8 kHz may not fit under 1 MB. In this case, the tool truncates the audio to the maximum duration that fits within the 1 MB target at 8 kHz. The results panel shows the duration preserved so you know exactly how much audio was kept. For a 1 MB limit at 8 kHz mono, approximately 60 seconds of audio can be preserved. For stereo audio, this is halved to about 30 seconds.