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Base64 Converter

Encode and decode Base64 online for free. Convert text, strings, and files to Base64 and back. Supports data URI generation, URL-safe encoding, instant browser processing with privacy guarantee.

Base64 Converter is a free online developer tool that works right in your browser — whatever you enter is processed locally and never sent to a server. No installation, no signup; works on both phone and desktop, ready to use instantly.

Code tools designed for developers with syntax highlighting, real-time validation, and formatting. Full coverage of JSON, XML, YAML, SQL, and more.

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How to use

  1. 1 Open the Base64 Converter tool page.
  2. 2 Paste your text, URL, or data into the input area.
  3. 3 Choose the operation mode and parameters.
  4. 4 Run the tool and review the result.
  5. 5 Copy or download the result.

Why we built this tool

As developers ourselves, we kept switching between scattered tools that sent our code to unknown servers. We built this developer suite so formatting, validation, and conversion all run locally — your code stays yours.

About Base64 Converter: what you should know

Developers handling JWTs, SSO tokens, binary data in web contexts, or email attachments. Base64 is everywhere in modern web stacks — it encodes OAuth client secrets, data URIs for inline images, and file uploads to APIs that expect string payloads instead of multipart form data.

Key features

  • Text ↔ Base64 with UTF-8 Awareness — Unicode characters, emoji, and accented letters all encode and decode correctly. Traditional ASCII-only converters silently corrupt non-English strings — this one handles the full UTF-8 range.
  • File-to-Base64 Data URI — Drag an image or document and get a complete `data:image/png;base64,...` string ready to paste directly into HTML or CSS. Useful for embedding small assets without an extra network round-trip.
  • JWT Header Payload Inspector — Paste a JWT token and instantly see the decoded header and payload JSON — great for quickly verifying which claims (issuer, expiry, audience) are present without spinning up a JWT debugging service.

Common use cases

  • Building Data URI Inline Assets — Inline small SVG icons or favicons into a single CSS file to reduce HTTP requests during initial page load. Base64-encode the file first, then wrap it with the correct data URI prefix.
  • Encoding OAuth Client Secrets — Many OAuth providers send client_id:client_secret pairs as Base64-encoded Basic Auth credentials. Encode the pair on this tool before hitting the /token endpoint — saves you from wrestling with curl headers manually.

Frequently Asked Questions

Is this tool free?

Yes, completely free with no signup required.

Can I use it on mobile?

Yes, it works on mobile browsers with touch support.

What category does this belong to?

Developer

Which programming language formats are supported?

Supports JSON, XML, YAML, SQL, CSV, TOML and more, plus code format conversion for Java, Python, TypeScript, etc.

What code and data formats are supported for formatting and validation?

ToolPure supports JSON, XML, YAML, TOML, CSV, SQL, and Markdown formatting. Validation includes syntax checking, schema validation for JSON, and well-formedness checking for XML.

Can I convert between different data formats?

Yes, you can convert between JSON, XML, YAML, CSV, and TOML. The converter preserves data types, nested structures, and array indices during conversion.

Is there a file size limit for code formatting?

Files up to 10MB can be formatted without issues. For larger files, the tools use Web Workers to prevent UI freezing. Syntax highlighting supports files with up to 100,000 lines.

Is Base64 Converter safe? Is my data uploaded or stored?

Yes. Base64 Converter is a pure front-end tool: whatever you type or paste is processed only in your browser's memory and never sent to a server. It disappears as soon as you refresh or close the page.

🔒 Privacy & Security：All processing happens locally in your browser. Files are never uploaded or stored.

🔒 Privacy: All processing happens locally in your browser. Your files and data never leave your device — no upload, no server, no tracking.

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