Source: https://mactoolbox.app/glossary/lossless-vs-lossy

# What is the difference between lossless and lossy?

By Nikhil Barik · Published November 3, 2026

## Quick answer

Lossy compression throws away some detail to make files much smaller, as JPEG and MP3 do. Lossless compression shrinks files without losing anything, as PNG and FLAC do.

## What the terms mean

A lossless file can be restored to exactly the original data. A lossy file cannot, and each time you re-save it in a lossy format it can lose a little more.

## Which formats are which

- Lossless: PNG, FLAC, WAV, AIFF, TIFF.
- Lossy: JPEG, MP3, AAC (M4A), H.264, HEVC.
- HEIC and WebP can be either, depending on how they are saved.

## Why it matters on a Mac

Keep lossless masters for editing and archiving. Use lossy copies for sharing, where size matters more than perfect detail.

## How Toolbox handles it

Convert Audio and Extract Audio offer lossless WAV and FLAC alongside lossy MP3 and M4A. Convert Images offers PNG and TIFF as well as JPEG. Toolbox saves new copies and does not change your originals.

## Frequently asked questions

**Is FLAC the same as WAV?**

Both are lossless. FLAC is compressed and about half the size of WAV, which is uncompressed.

**Can I turn a lossy file back into lossless?**

You can change the format, but the lost detail does not come back.

**Does converting JPEG to PNG improve quality?**

No. It only stops further loss.

## Tools mentioned

- [**Convert Audio**: Change audio files to MP3, M4A, WAV, FLAC or AIFF.](https://mactoolbox.app/convert-audio-to-mp3-mac)
- [**Extract Audio**: Save the soundtrack of a video as an audio file.](https://mactoolbox.app/extract-audio-from-video-mac)
- [**Convert Images**: Save photos as JPEG, PNG, HEIC, TIFF or WebP.](https://mactoolbox.app/heic-to-jpg-mac)

## Keep reading

- [Convert Audio](https://mactoolbox.app/convert-audio-to-mp3-mac)
- [Extract Audio](https://mactoolbox.app/extract-audio-from-video-mac)
- [Convert Images](https://mactoolbox.app/heic-to-jpg-mac)