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Base64 Encoder / Decoder

Developer Tools

Encode and decode Base64 text

Quick Answer

Base64 Encoder / Decoder: Encode and decode Base64 text. Base64 Encoder / Decoder uses standard developer formulas to compute accurate results instantly.

Input

Output

Input bytes20
Output chars28
Size overhead+40%
VariantStandard

How encoding works (first 3 bytes)

  1. 1First 3 byte(s) → binary: 11100100 10111000 10000000
  2. 2Split into 6-bit groups: 111001 | 001011 | 100010 | 000000
  3. 3Indices 57, 11, 34, 0 → chars "5LiA"
  4. 43 bytes → 4 chars, no padding needed

Base64 index table

Index0-2526-5152-616263Padding
CharA-Za-z0-9+/=

💡 Base64 is an encoding, NOT encryption — anyone can decode it. Every 3 bytes become 4 chars (about 33% larger). Use the URL Safe variant in URLs and filenames.

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How to Use

  1. Paste or type content: drop code/text into the Base64 Encoder / Decoder or fill the parameters.
  2. Choose mode/options: switch format, rules or processing as needed.
  3. Live output: results appear instantly — nothing is submitted, data stays in your browser.
  4. One-click copy: copy the output straight into your development environment.

Key Points

  • Base64 Encoder / Decoder is a free online developer tool — open and use, no sign-up.
  • All calculations run locally in your browser; your data never leaves the device.
  • Key capability: Encode and decode Base64 text.
  • Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

Base64 Encoder / Decoder formula

Base64 Encoder / Decoder uses standard developer formulas to compute accurate results instantly.

FAQ

How do I use the Base64 Encoder / Decoder?
Open the page and fill in the input fields — results update automatically. Encode and decode Base64 text.
Are the results accurate?
Yes. Standard formulas and conversion factors are used and verified.
Is it free? Do I need to sign up?
Completely free. No registration, login or download required.
Does it work on mobile?
Yes. The responsive design works on phones, tablets and desktops.
Is my data saved?
No. Everything runs locally in your browser.

Related Tools

Related Guides

Source & Updates

Based on RFC 4648, ECMA-262 and related specifications. Last updated: 2025-07

Authoritative sources:

Last updated:

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Maintained and periodically reviewed by the YiJianSuan editorial team — review process in ourEditorial Policy.

Cite this page: YiJianSuan. Base64 Encoder / Decoder[EB/OL]. https://www.yijiansuan.com/en/c/dev/base64

Results provided by this tool are for reference only and do not constitute professional advice.