Run-length encoding (RLE)

Client

Classic run-length encoding for repeated characters—illustrates lossless compression ideas without binary file handling.

Compress repeated letters to counts (AAAB → 3A1B) or expand RLE back—client-side string toy.

About Run-length encoding (RLE)

Compress repeated letters to counts (AAAB → 3A1B) or expand RLE back—client-side string toy. The interactive transform on this page runs in your browser tab—Toolcore does not need your paste for the core operation described above.

How to use this page

Paste or type in the main workspace, run the primary action from the toolbar, then copy or download the result. Use Load example when the page offers it, or URL prefill (?q= / ?qb=) so agents and tickets open the same input.

3A2B1C

Common use cases

  • Demonstrate RLE in compression or algorithms courses.
  • Quickly expand or create count+char strings for puzzles.

Common mistakes to avoid

  • Mixed case runs

    A and a are different characters—runs must match exactly.

FAQ

Is this gzip?

No—this is a simple teaching RLE, not a production codec.

How to decode?

Paste digit-led RLE like 3A2B—the tool detects and expands it.

Related utilities you can open in another tab—mostly client-side.