Check the full stereo file for opposite polarity, then invert the left, right, or both channels without reversing playback.
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This flips waveform polarity; it does not play the audio backward. To repair left/right cancellation, invert one channel, not both.
Audio polarity inversion multiplies every sample in the selected channel by -1. It flips the waveform vertically while preserving timing, pitch, and playback direction.
If one stereo channel closely matches the negative of the other, written as L ≈ -R, shared content can become very quiet or disappear when the channels are combined to mono. Inverting either one channel restores their relative polarity.
The detector evaluates the complete audio timeline rather than only the beginning. It excludes silent and extremely quiet sections, measures correlation, level matching, mono fold-down loss, and time coverage, and reports cases where opposite polarity appears only in parts of the file.
A stereo comparison cannot determine which side has the intended absolute polarity. Invert either the left or right channel to repair relative cancellation; inverting both usually preserves the same left-versus-right relationship. Preview the result before exporting. Processing stays in this browser tab.
Polarity inversion multiplies every sample in the selected channel by -1. The waveform flips vertically, but its timing, pitch, and playback direction stay the same. Reversing audio instead changes the order in which samples play.
When the right channel closely matches the negative of the left channel, combining them to mono can make shared content much quieter or cancel it almost completely. Inverting either one channel restores their relative polarity. Inverting both does not repair that cancellation.
The check samples the complete audio timeline, ignores silent and extremely quiet sections, and evaluates correlation, level matching, mono fold-down loss, and how consistently the condition appears. It reports partial or uncertain cases separately instead of treating every negative correlation as a fault.
The analysis can identify the relationship between the left and right channels, but it cannot know which channel has the intended absolute polarity. If the channels are matching opposites, invert either the left or the right channel, preview the result, and keep the choice that fits your signal chain.
Related tools: Audio Channel Converter · Stereo to Mono · Mono to Stereo · Extract Left · Extract Right · Swap Channels