Free Online Base64 Encoder & Decoder — Text, Images & File Converter

Overview: Encode & Decode Text, Images & Files to Base64

Encode text and binary files to Base64 strings, or decode Base64 data back to plain text or downloadable files. All computations and data processing are executed 100% locally on your device using client-side WebAssembly, HTML5 Canvas, and modern Web APIs without uploading files to any external server.

Supported Formats

Base64 Encoder & Decoder supports the following file formats:

  • .txt — client-side processing support.
  • .bin — client-side processing support.
  • All files — client-side processing support.

How to Use Base64 Encoder & Decoder in Browser

  1. Choose Encode or Decode: Select whether you want to encode text/files to Base64 or decode from Base64.
  2. Enter Input: Type text, paste Base64 code, or drop any file.
  3. Copy or Save: Copy the resulting Base64 string or download the decoded output file.

Key Features & Privacy Protections

  • 100% Client-Side Privacy: Zero cloud upload. Your documents, photos, and files never leave your local browser sandbox.
  • Zero Installation: Runs instantly in Chrome, Safari, Firefox, Edge, Android, and iOS browsers.
  • Free Forever: No sign-up, no subscriptions, no ads, and no file size limits.

Frequently Asked Questions (FAQ)

Can I convert images to data:image/png;base64 URLs?

Yes, it generates ready-to-use Data URI strings for HTML/CSS embedding.

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v1.0.0Free · Web CryptoDeveloper Tools

Free Online Base64 Encoder & Decoder — Text, Images & File Converter

Encode & Decode Text, Images & Files to Base64. Encode text and binary files to Base64 strings, or decode Base64 data back to plain text or downloadable files.

What is Base64 Tool and what does it do?

The Base64 Encoder & Decoder is a comprehensive developer tool for converting plain text, code snippets, images, and binary files into Base64 format — and decoding Base64 strings back into original files and text. It supports standard Base64, URL-safe Base64, and ready-to-use HTML/CSS Data URIs.

Everything runs entirely in your local browser sandbox using native WebCrypto and binary buffer APIs. You can encode sensitive API keys, auth headers, and confidential images with complete peace of mind.

  • Encode plain text, UTF-8 strings, and source code into standard Base64 format.
  • Decode Base64 encoded strings back into clean, readable text.
  • Convert images and binary files into `data:image/png;base64` Data URIs for inline CSS/HTML.
  • Decode Base64 string data directly into downloadable original binary files.
  • URL-safe Base64 mode and one-click copy to clipboard with character count statistics.

How does Base64 Tool work?

The tool utilizes native binary buffer pipelines and the WebCrypto API. Text is converted into a UTF-8 Uint8Array byte buffer, grouped into 6-bit chunks, and mapped onto the 64-character ASCII index table (A-Z, a-z, 0-9, +, /).

For decoding, the 64-character alphabet indices are translated back into 8-bit octets and decoded into UTF-8 text strings or binary File Blobs ready for immediate disk download.

100% private: all processing happens locally in your browser using client-side WebAssembly, HTML5 Canvas, and modern Web APIs. Your files are never uploaded to any server.

Who needs Base64 Tool?

Frontend Developers

Embed small icons, custom fonts, and vector graphics directly into CSS and HTML as Data URIs to eliminate HTTP requests.

Backend & API Developers

Generate and decode HTTP Basic Auth headers, JWT token payload segments, and webhook payloads.

Security & Network Engineers

Analyze encoded email headers, SAML response assertions, and obfuscated configuration payloads.

Students & Computer Science Learners

Understand how binary-to-text serialization algorithms, bit masking, and padding work in practice.

Supported file formats

Base64 Encoder & Decoder processes the following file extensions and data formats directly in your browser:

.txt.binAll files

How to use Base64 Tool — step by step

  1. 1

    Choose Encode or Decode

    Select whether you want to encode text/files to Base64 or decode from Base64.

  2. 2

    Enter Input

    Type text, paste Base64 code, or drop any file.

  3. 3

    Copy or Save

    Copy the resulting Base64 string or download the decoded output file.

Frequently asked questions

Can I convert images to data:image/png;base64 URLs?

Yes, it generates ready-to-use Data URI strings for HTML/CSS embedding.

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