Fix the mix before the master
Listen all the way through your stereo mix. Check for clicks, an abrupt ending, distorted vocals and bass that overwhelms the rest of the track. Mastering treats the combined audio; it cannot move one instrument independently or recover a clipped recording. Make those decisions in your session first.
Leave room for processing without clipping the export. There is no required magic peak level or LUFS number for importing a mix. If a limiter is already part of the sound you intend, keep a version with it and a version without so you can compare deliberately.
Export a useful source
Prefer the original lossless WAV or FLAC over a file copied from a lossy stream. WAVLNGTH also accepts supported MP3, M4A, AAC, OGG and AIFF files, subject to browser decoding. Changing a lossy file’s extension or converting it to WAV does not restore discarded detail.
The tool accepts files up to 100 MB and six minutes, with a decoded-audio safety limit. Keep your original export untouched. Use descriptive file names that separate the source mix from your mastered versions.
Audition more than the loudest section
Choose a character and begin with moderate intensity. Listen to the intro, the densest chorus and the quietest passage. Compare with level matching enabled so a louder treatment does not win by volume alone. If cymbals get brittle, the bass loses definition or a vocal gets pushed back, reduce intensity or try another character.
The optional −1 dBTP ceiling provides true-peak headroom in the export. It is not an instruction to force every song to one integrated loudness. Check the final 24-bit, 44.1 kHz WAV on the headphones or speakers you know before you distribute it.
Keep mastering and sharing separate
Standalone mastering runs on your device. The song is not uploaded to render the master. Creating a free account unlocks unlimited mastering after the guest trial; account requests still go to the website’s servers.
If you choose to submit a master to a live reviewer, the selected file is uploaded for that host. The host may broadcast their review. That is a separate action from exporting a master, and mastering during submission is always optional.