Lossless vs Lossy Compression
This comparison covers Lossless vs Lossy Compression within Compression for GCSE Computer Science. Revise Compression in 3.3 Data Representation for GCSE Computer Science with 16 exam-style questions and 16 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 8 of 12 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 8 of 12
Practice
16 questions
Recall
16 flashcards
Lossless vs Lossy Compression
| Aspect | Lossless | Lossy |
|---|---|---|
| Data Loss | None - perfect reconstruction | Permanent - some data removed |
| Compression Ratio | 30-70% smaller (moderate) | 80-95% smaller (extreme) |
| Reversible | Yes - decompress to exact original | No - cannot recover lost data |
| Best For | Text, programs, medical images, legal docs | Photos, music, video, web images |
| Examples | PNG, ZIP, FLAC, GIF | JPEG, MP3, MP4, AAC |
| When to Use | When every bit matters / exact copy needed | When human perception is primary concern |
Keep building this topic
Read this section alongside the surrounding pages in Compression. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Compression
Which statement correctly describes lossy compression?
Explain how run-length encoding (RLE) works to compress data.
Quick Recall Flashcards
16 questions on Compression — practise free
Instant marking, adaptive difficulty, and 16 spaced repetition flashcards. Free until your GCSEs.
Try PrepWise Free