| Set | Size | Bytes/Char | Coverage | Use Case |
|---|---|---|---|---|
| ASCII | 128 chars | 1 byte | English only | Legacy systems, simple text |
| Extended ASCII | 256 chars | 1 byte | Western Europe | Legacy, regional documents |
| Unicode (UTF-8) | 143,859 chars | 1-4 bytes | All languages | Web, modern apps, files |
| Unicode (UTF-16) | 143,859 chars | 2-4 bytes | All languages | Windows, Java internals |
| Unicode (UTF-32) | 143,859 chars | 4 bytes | All languages | Internal processing |
This comparison covers Character Set Comparison within Character Sets for GCSE Computer Science. Revise Character Sets in 3.3 Data Representation for GCSE Computer Science with 15 exam-style questions and 18 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 7 of 11 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Character Sets
How many bits does standard ASCII use to represent each character?
Explain why using Unicode to store a text file produces a larger file than using ASCII to store the same text.