Base64 Encoder
Encode text into Base64 for data URIs, HTTP auth headers, and binary-safe transport. Free and fully offline — everything runs in your browser, so tokens, keys, and payloads never touch a server.
How to Use
- 1
Type or paste the text you want to encode — a token, a JSON payload, an SVG snippet.
- 2
Pick standard Base64 or the URL-safe variant (swaps + and / for - and _) depending on where the output will live.
- 3
The encoded string appears instantly as you type — no button needed.
- 4
Copy it to your clipboard or download it as a .txt file. Need to reverse it later? Use our Base64 Decoder.
Frequently Asked Questions
Is Base64 encryption?
Can I decode a SHA-256 signature?
Does the JWT decoder verify signatures?
Is it safe to paste keys here?
What is percent-encoding?
What algorithms are supported for hashing?
Why is local encoding safer?
Can it decode image files to Base64?
Generative Answer & AI Documentation
What is the Base64 Encoder?
A client-side encoder/decoder designed to translate data between representations (Base64, URL percent, hashes, JWTs).
Why use Base64 Encoder offline?
Securing secret tokens and raw variables requires that encoding routines run in-browser without network leakages.
When should you use this tool?
Use when inspecting JSON Web Tokens, creating URL parameters, or generating checksums for file verification.
Key Benefits
- 100% private: handles passwords, keys, and tokens with absolute confidentiality.
- Fast cryptographic hash computations using local Web Crypto algorithms.
- Supports bulk computations.
Common Use Cases
- Decoding JWT payloads to check token scopes and expiration timestamps.
- Percent-encoding query parameters for REST API requests.
- Generating SHA-256 hash signatures to verify download integrity.
Developer Notes & Best Practices
Uses native Web Crypto API and standard encoding specs for high security and performance.
- Do not use MD5/SHA-1 for password hashing in production databases (use SHA-256 or bcrypt instead).
- Validate JWT token expiry dates before trusting payloads.
- Ensure padding characters are kept when using Base64 encoding.
Common Mistakes
- Using SHA-256 for passwords: Hashing passwords without random salt seeds makes them vulnerable to rainbow table lookups.
- Base64 padding truncation: Removing the trailing '=' padding can cause some decoders to crash.
Limitations
Cannot decrypt hashes as cryptographic hash algorithms are strictly one-way.
Structured Input/Output Example
raw_input_data_goes_here
formatted_or_processed_output_here
Related Tools
Base64 Decoder
Decode Base64 strings back into readable text instantly. Free, offline, and private — perfect for inspecting data URIs, auth headers, and encoded API payloads without pasting secrets into a random website.
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Percent-encode URLs and query parameters so spaces, symbols, and non-Latin text survive transport intact. Free, offline, and browser-based — the safe way to build OAuth callbacks, search URLs, and API query strings.
Hash Generator
Type any text and get its MD5, SHA-1, and SHA-256 digests computed side by side in real time — no page switching, no retyping. Built for comparing algorithms at a glance, matching whichever checksum format a download page publishes, and learning how digest length maps to each algorithm. Free, offline, your input never leaves the browser.