What is URL-safe Base64?

Standard Base64 contains '+' and '/' characters, which have special meanings in URLs. URL-safe Base64 replaces '+' with '-' and '/' with '_', making it safe for query parameters and URL tokens.

Can I swap the input and output easily?

Yes, clicking the 'Swap ⇄' button moves the output to the input panel so you can immediately verify round-trip fidelity.

All Developer Tools

Base64 Encoding Engine

Base64 Encoder & Decoder

Fast, reliable Base64 encoding and decoding with complete UTF-8 Unicode, international character, and emoji safety.

100% In-Browser Client-Side — Zero Server Uploads

URL-Safe (- and _)

Successfully encoded to Base64 (UTF-8 safe)

96 B1 lines

Raw Text / UTF-8 Input

Upload

1 lines•68 chars

72 B

Base64 Output

V2VsY29tZSB0byBQaWNvRml4IERldmVsb3BlciBUb29scyEg8J+RiyDwn5qAIDEwMCUgSW4tQnJvd3NlciAmIFByaXZhdGUu

1 lines•96 chars

96 B

UTF-8 Safe Base64 Encoding & Decoding

Why traditional online Base64 converters fail and how PicoFix solves character corruption.

True UTF-8 & Emoji Round-Trip

Standard JavaScript btoa() only handles 8-bit Latin-1 code points, throwing errors or replacing symbols with question marks when emojis or non-English characters appear. PicoFix encodes raw multi-byte UTF-8 typed arrays for 100% roundtrip fidelity.

URL-Safe Base64 Format

Standard Base64 contains + and / characters that break URLs and query parameters. Enable URL-Safe mode to substitute + with - and / with _ according to RFC 4648 §5 specifications.

Swap ⇄ Verification

Verify any encoding or decoding operation instantly using the Swap button. Toggle back and forth between plaintext and ciphertext without tedious copy-pasting.

Base64 Encoder & Decoder FAQs

Helpful answers to common image compression questions.

Traditional web tools use legacy window.btoa without UTF-8 byte encoding, which crashes or corrupts characters beyond Latin-1. PicoFix uses TextEncoder and TextDecoder to guarantee 100% accurate multi-byte UTF-8 handling.

Related Developer Tools

View all tools →

URL Encoder / Decoder

Encode and decode URLs, query strings, and path components with component and full URI modes.

Open tool

JSON Formatter & Validator

Format, beautify, minify, and validate JSON client-side with precise line and column error indicators.

Open tool

Unix Timestamp Converter

Convert Unix epoch timestamps to UTC and local date/time formats, with live clock and calendar picker.

Open tool