Staaarter Tools

List Base64 Encoder

Base64-encode every item in a list on its own, so the output list has exactly the same number of items as the input, each one replaced by its own Base64 string, instead of Base64-encoding the whole joined text as a single blob. A free online tool from Staaarter, right in your browser.

Runs locallyUpdated 2026-07-27
listbase64encoding

Overview

Introduction

Base64-encoding a list of values one at a time, IDs, tokens, or short strings for a config file or API payload, gets tedious fast if you have to run each one through an encoder individually.

This tool encodes an entire list in one pass while keeping each item's Base64 string separate, rather than mashing the whole list into a single encoded blob.

What Is List Base64 Encoder?

The List Base64 Encoder is a per-item encoder: it splits your input on the chosen separator and Base64-encodes each resulting item independently.

It's deliberately distinct from a whole-text Base64 encoder, which would encode your entire input, separators included, as one opaque string that loses the item boundaries.

How List Base64 Encoder Works

The input is split into items on your chosen separator, trimmed, and blank items are dropped.

Each item is UTF-8 encoded to bytes and passed through the browser's native `btoa()` after converting the bytes to a binary string, then the resulting Base64 strings are rejoined with your chosen separator.

When To Use List Base64 Encoder

Use this when you need a list of Base64-encoded tokens, IDs, or short strings, for example preparing a batch of values for a config file, environment variables, or an API payload.

It's a better fit than the plain Base64 Encoder whenever you care about keeping individual items distinguishable in the output rather than one combined blob.

Often used alongside List Base64 Decoder, Base64 Encoder and List URL Encoder.

Features

Advantages

  • Preserves item boundaries and count, unlike encoding the whole list as one string.
  • UTF-8 safe, so non-ASCII characters in your list items encode correctly.
  • Works with any separator, newline, comma, or a custom delimiter.

Limitations

  • Doesn't produce a single combined Base64 blob, if that's what you need, use the whole-text Base64 Encoder instead.
  • Very long individual items produce correspondingly long Base64 strings, there's no line-wrapping applied.

Examples

Encoding a short list

Input

admin
editor
viewer

Output

YWRtaW4=
ZWRpdG9y
dmlld2Vy

Each role name is encoded independently, giving three Base64 strings, one per input item.

A list with non-ASCII text

Input

café
naïve

Output

Y2Fmw6k=
bmHDr3Zl

Both items are UTF-8 encoded to bytes first, so accented characters encode correctly.

Best Practices & Notes

Best Practices

  • Use this instead of the whole-text encoder whenever you need to keep individual values addressable after encoding.
  • Pair with the List Base64 Decoder to verify a batch round-trips correctly before relying on it elsewhere.

Developer Notes

Each item is UTF-8 encoded via `TextEncoder`, converted to a binary string with `String.fromCharCode()` per byte, then passed to the native `btoa()`, the same UTF-8-safe pattern the string category's whole-text Base64 Encoder uses, just applied per item instead of once.

List Base64 Encoder Use Cases

  • Preparing a batch of tokens or IDs for a config file that expects Base64 values
  • Encoding a list of short secrets or identifiers for transport in a URL-safe-adjacent format
  • Generating Base64 test fixtures for a batch-processing script

Common Mistakes

  • Expecting one combined Base64 string for the whole list, this tool intentionally keeps items separate; use the whole-text encoder if you want one blob.
  • Forgetting that Base64 output can contain "+", "/", and "=" characters, which may need further escaping if you're embedding the result in a URL.

Tips

  • If your downstream system needs URL-safe Base64, you'll need to replace "+"/"/" with "-"/"_" afterward, standard Base64 isn't URL-safe by default.
  • Use the comma separator if you're feeding the encoded list straight into a CSV field.

References

Frequently Asked Questions