Guide
Open the editorShort answers to the questions that come up when you send a recording. Always follow the rules of the place you send it to; this tool cannot guarantee acceptance.
My rules say “MB”. Which unit do I choose?
Choose MB for 1,000,000 bytes and MiB for 1,048,576 bytes. If the rules only say “MB”, MB is the safer reading because it is the smaller limit.
Type the number exactly as written. The tool compares whole bytes, and shows the byte count under the box.
Why is my MP3 a little longer than the selection?
MP3 stores audio in frames and adds a few milliseconds at the start and end. The result shows the measured length, including this padding.
If you are close to a length limit, end the selection a little earlier or save as WAV.
WAV or MP3? Which quality?
WAV keeps the samples exactly but makes a larger file. MP3 makes a smaller file; a higher bitrate sounds better and is larger.
Bitrates that change the requested output rate are disabled. Select output rate first.
The rules ask for mono, but my file is stereo
Choose Mono under Submission specs; all channels are averaged, opposite phases may cancel.
Choose the required output rate. Listen to the final file and check its measured channels/rate.
What does the volume check mean?
The tool shows the loudest point after your change. If it would break up (clip), saving is blocked until you lower the volume. MP3 needs a little extra room.
Some receivers ask for a lower peak (for example −3 dB). Lower the volume until the loudest point shown is at or below that value.
Examples of receiver rules
Quoted from public help pages as read on 2026-10-13. They may change, and they apply only to those services. Check the current page before you send.
Voices.com — demos and auditions
Read 2026-10-13 · page shows last modified 2021-03-05 · voices.com/help/knowledge/faq/how-large-can-my-files-be
- MP3, 128 kbps, 44.1 kHz.
- Largest file for an audition or demo: 10 MB.
- No length, bit depth or mono/stereo rule is stated there.
- Choose MP3, output44,100Hz,128kbps.
- Enter 10 as the maximum size with the unit MB.
Voice123 — proposals and samples
Read 2026-10-13 · no date shown on the page · support.voice123.com/hc/en-us/articles/207612656
- MP3, constant bitrate 96–128 kbps, 44.1 kHz, 16-bit, mono, smaller than 100 MB.
- Peaks no higher than −3 dB; no emojis in file names.
- Choose Mono and output44,100Hz under Submission specs.
- Choose MP3 and 96 or 128 kbps, and lower the volume until the loudest point is −3 dBFS or lower.