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Base64 Encoder / Decoder

Use this Base64 encoder / decoder to inspect API payloads, URL-safe tokens, QR text, config snippets, and copied encoded strings before sharing or debugging.

Method shown June 6, 2026Source note includedFree tool

Live converter

Base64 encoder / decoder

Encoded Base64
VG9vbGtpdCBTaGVsZjogSGVsbG8sIOS4lueVjA==
StatusReady

Standard Base64. Padded.

Input size24 chars

28 UTF-8 bytes represented in the transformation.

Base64 summary

Quick size check for copying into URLs, APIs, headers, or QR payloads.

MeasureValue
Text input24
UTF-8 bytes28
Output characters40
VariantStandard Base64
Encoding note

Base64 is an encoding, not encryption. It makes bytes easier to move through text-only systems, but anyone can decode the value.

Quick answer

Base64 Encoder / Decoder: what it generates

Base64 Encoder / Decoder generates encoded or decoded text from text input, base64 input, mode, output variant and padding. The visible generation method is Base64 output = UTF-8 bytes grouped into 6-bit values and mapped to the Base64 alphabet.

Draft outputEncoded or decoded text
InputsText input, Base64 input, Mode, Output variant, Padding
Generation methodBase64 encoding method

Generation method

Base64 encoding method

Base64 output = UTF-8 bytes grouped into 6-bit values and mapped to the Base64 alphabet

Base64 is encoding, not encryption. URL-safe Base64 replaces + and / with - and _ and may omit padding.

How to use

Steps

  1. Choose whether to encode text or decode a Base64 value.
  2. Select standard or URL-safe Base64 output.
  3. Turn padding on or off when encoding if the target system expects one style.
  4. Review the output, byte count, and padding note before copying.

Example

Sample output

TextToolkit Shelf
Base64VG9vbGtpdCBTaGVsZg==
URL-safe optionUses - and _ instead of + and /

Generator use

Best for

  • Use this Base64 encoder / decoder to inspect API payloads, URL-safe tokens, QR text, config snippets, and copied encoded strings before sharing or debugging.
  • Generating base64 encoding method with the method and assumptions visible.
  • Comparing the output with the sample output and benchmark table before using it elsewhere.
  • Browser-side link, file, format, and web utility tasks that need an output now.

Before relying on it

Check first

  • Using the encoded or decoded text without checking that text input, base64 input and mode, and additional inputs match the same task and context.
  • Ignoring that base64 is encoding, not encryption. URL-safe Base64 replaces + and / with - and _ and may omit padding.
  • Skipping the source notes when the formula, benchmark, or warning depends on outside context.
  • Publishing a generated file or code without testing it in the real destination.

Details

What to know before using the output

These notes make the assumptions explicit, especially where the same search query can mean slightly different things.

Text basisUTF-8 bytes

Unicode text is encoded as UTF-8 before Base64 conversion, so non-ASCII characters round-trip correctly.

URL-safe mode- and _ alphabet

URL-safe Base64 avoids + and / characters that can require escaping inside URLs, filenames, and tokens.

SecurityNot encryption

Anyone can decode Base64. Do not treat encoded tokens, credentials, or customer data as protected.

Source notes

References used for this generator

RFC 4648Defines Base64 and Base64URL alphabets, padding behavior, and common base encoding rules.MDN Web DocsDocuments Base64 encoding and decoding concepts for web APIs.

Benchmarks

How to read the output

This generator is a drafting aid, not a fixed rule. Use the output to compare options and document your assumptions. Benchmark ranges are broad planning heuristics unless this page names a specific source for the range.

Standard Base64: + / =.

Common in email, data URLs, basic auth, and many API examples.

URL-safe Base64: - _ optional padding.

Common in URL tokens and systems that avoid reserved URL characters.

Size change: About 33% larger.

Base64 usually expands binary data because it stores bytes in printable text form.

Method and limitations

Methodology and assumptions

The generation method, inputs, example, and limitations are shown so the draft output is checkable, not treated as final copy.

Generation method

Base64 output = UTF-8 bytes grouped into 6-bit values and mapped to the Base64 alphabet

Inputs used

Text input, Base64 input, Mode, Output variant, Padding

Limitations

Utility outputs depend on the encoded payload, file format, target app, scanner, printer, browser, and real-world testing before sharing.

Last reviewed

June 6, 2026

Cite this page

Toolkit Shelf. Base64 Encoder / Decoder. Last reviewed June 6, 2026. https://toolkitshelf.com/tools/base64-encoder-decoder

FAQ

Common questions

Is Base64 encryption?

No. Base64 is reversible encoding. It can make data easier to transport as text, but it does not hide the contents.

What is URL-safe Base64?

URL-safe Base64 replaces + with - and / with _, and some systems remove trailing equals padding.

Why does decoded Base64 sometimes show an error?

The input may contain invalid Base64 characters, broken padding, missing data, or bytes that are not valid UTF-8 text.

Do utility tools upload my payload?

Use the page notes for each tool. Browser-side utilities can generate outputs locally, but the final file or code may still reveal whatever you encode or share.

Why should I test the generated output?

Scanners, printers, file viewers, apps, and platform previews can behave differently, so test the exact downloaded output before using it publicly.

Why might another generator show a different output?

Different tools may use different rounding, assumptions, default rates, methods, formulas, or input timing. Compare the visible method and inputs before relying on the output.