# lossless

CEFR C1 · Adjective

Source: https://englishreference.com/word/lossless
Updated: 2026-10-16

## Definition

keeping every bit of original quality when a file is made smaller. You use it for music, photos, or video that still look or sound perfect after compression.

For teachers: retaining all original data during compression, so the reconstructed file is identical to the source. Typically contrasted with 'lossy', which discards data to achieve smaller file sizes.

## Examples

- This music file is lossless, so it sounds perfect.
- She downloads lossless audio files because she can hear the difference on good headphones.
- The archive stores scans in a lossless format, preserving every detail of the original manuscripts for future restoration work.

## Antonyms

lossy

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