Base64, URL encoding and UUIDs explained simply
By SyncBuilder
When you work with APIs and data, three small tools come up again and again: Base64, URL encoding and UUIDs. None of them is complicated, but mixing them up leads to broken links, corrupted payloads and duplicate records. Here is what each one does and when to reach for it.
What each tool actually does
Base64 encodes binary data as plain text so it survives text-only channels like email, data URIs and tokens. It makes the data about a third larger, and it is not encryption. URL encoding, also called percent-encoding, escapes characters that are unsafe in a URL or query string, such as spaces and ampersands, so a value can be passed safely inside a link. A UUID is a 128-bit unique identifier; version 4 is randomly generated, so two systems can create unique keys without coordinating.
When to use which
- Base64: embedding images inline or attaching binary data inside a JSON payload.
- URL encoding: passing values as query parameters or building redirect links.
- UUIDs: primary keys, request IDs and idempotency keys that must stay unique.
Base64 is encoding, not security. Never treat a Base64 string as if it were encrypted or hidden; anyone can decode it back to the original in seconds.
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