What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that represents binary data as ASCII characters. It uses 64 characters (A-Z, a-z, 0-9, +, /) plus = for padding.

What is URL-safe Base64?

URL-safe Base64 replaces + with - and / with _ to avoid conflicts with URL special characters. The padding = may also be omitted.

Does Base64 encoding provide security?

No. Base64 is an encoding, not encryption. Anyone can decode it. Never use it to protect sensitive data.

Base64 Encode

Encoding Tools

Encode text to Base64 with URL-safe variant option

By DevToolHQ teamUpdated 2026-04-15100% client-sideMethodology

100% client-side processing

Input Text

URL-safe variant

About Base64 Encode

Base64 encoding converts arbitrary binary data to a subset of printable ASCII characters — specifically the 64 characters A–Z, a–z, 0–9, plus + and / (with = for padding). Every 3 bytes of input become 4 output characters, so Base64 increases data size by about 33%. The most common reason to Base64-encode in web development is embedding binary data in text-safe contexts: data URIs for images embedded directly in HTML or CSS, JSON payloads that need to carry binary content, HTTP Basic Authentication headers (username:password encoded as Base64), and email attachments via MIME encoding. It is also used heavily in JWTs, where the header and payload are Base64URL-encoded (a variant that swaps + for - and / for _ to make the output safe in URLs and HTTP headers). This tool supports both standard Base64 (RFC 4648) and the URL-safe variant. The URL-safe option also removes the = padding, which is the format used by most JWT libraries and OAuth tokens. Note that Base64 is encoding, not encryption — it is trivially reversible and provides zero security on its own. If you are encoding sensitive data to transmit it, you need actual encryption before or instead of Base64.