Javascript string compression for URL hash parameter

Question

I'm looking to store a lot of data in a URL hash parameter without exceeding URL character limits.

Are there any conventional ways of compressing string length which could be then decoded on another page load?

I've seen LZW encoding used for similar solutions, however would special characters be valid for this use?

Answer 1

LZW encoding technically works; you'll just need to convert the LZW-encoded binary into URL-safe base64, so that the output doesn't contain special characters. Here's an MDN article on base64 in JavaScript; the URL-safe variant of base64 just replaces + with - and / with _. Of course, you're not likely to reduce the size of your string by much by doing this, unless the data you want to store is extremely compressible.

Answer 2

You can look at smaz or shoco, which are designed for the compression of short strings. Most compression methods don't really get rolling until well after your URL length limit, so you need a specialized compressor for this case if you expect to get any gain. You can then encode the binary result using a scheme like Base 64 or a more efficient coding that uses all of the URI-safe characters.