Overview
Introduction
Building a batch of query parameter values, search terms, or path segments from a list often means every item needs percent-encoding before it's safe to put in a URL.
This tool encodes an entire list in one pass, applying `encodeURIComponent` to each item separately so the list's separator stays untouched and item boundaries stay clear.
What Is List URL Encoder?
The List URL Encoder is a per-item encoder: it splits the input on your chosen separator and percent-encodes each item independently with the same rules as JavaScript's `encodeURIComponent`.
It's distinct from encoding the whole list as one string, which would also escape the separator itself and merge the list into an unusable blob.
How List URL Encoder Works
The input is split into items on your chosen separator, trimmed, and blank items are dropped.
Each item is passed through `encodeURIComponent()`, which percent-encodes everything except letters, digits, and a small set of unreserved characters (`- _ . ! ~ * ' ( )`), then the encoded items are rejoined with your chosen separator.
When To Use List URL Encoder
Use this when preparing a batch of values, search terms, tags, filenames, to be used safely as URL query parameters or path segments.
It's also useful for quickly checking how a list of strings would look once percent-encoded, before building URLs programmatically.
Often used alongside List URL Decoder, URL Encoder and List Base64 Encoder.
Features
Advantages
- Keeps the list's separator intact by encoding items individually rather than the whole blob.
- Matches the exact escaping behavior of JavaScript's built-in `encodeURIComponent`, so results match what your code would produce.
- Works with any separator, so it fits lists copied from spreadsheets, CSV exports, or plain text files.
Limitations
- Uses component-level encoding rules, so characters like "/" and ":" are also escaped; it's not meant for encoding a full URL.
- Doesn't validate that the resulting encoded value is meaningful for a specific API, it only performs the escaping.
Examples
Best Practices & Notes
Best Practices
- Use this before appending a list of values to a URL as repeated query parameters, so each value is safely escaped.
- Keep the comma separator in mind if your downstream tool expects a comma-separated encoded list, this tool won't encode the comma between items, only within each item.
Developer Notes
Each item is passed directly to the native `encodeURIComponent()` function, so behavior matches exactly what the same call would produce in application code, no custom escaping logic is layered on top.
List URL Encoder Use Cases
- Preparing a batch of search terms or tags as safely encoded query parameter values
- Encoding a list of filenames or path segments before building download URLs
- Generating percent-encoded test fixtures for URL-parsing code
Common Mistakes
- Using this to encode a full URL, encodeURIComponent will also escape "/" and ":", breaking the URL structure; use it only on individual components.
- Forgetting that "+" in a query string traditionally means a space in some contexts, encodeURIComponent always uses "%20", not "+", for spaces.
Tips
- If a downstream system expects "+" for spaces instead of "%20", you'll need to replace it manually after encoding.
- Pair with List URL Decoder to confirm a batch of encoded values round-trips back to the originals.