Base64 encode text online

Base64 represents binary data as ASCII text using sixty-four safe characters plus optional padding. It is not encryption — anyone can reverse it — so treat Base64 as transport encoding for text channels that dislike raw bytes.

When you base64 encode text online, UTF-8 bytes become a compact alphabet of A–Z, a–z, 0–9, +, and /. That output fits JSON string fields, email bodies, and query parameters that would break on unescaped binary.

This base64 converter uses TextEncoder before btoa(), matching what Node.js Buffer.from(str, 'utf8').toString('base64') and Python base64.b64encode produce for the same input.

Encoded output grows roughly 33% compared to the original bytes. Small snippets encode instantly; very large pasted files may feel sluggish — use dedicated image or PDF tools for big binaries.

Type or paste text into the input panel. The Base64 output updates live as you edit. The string Hello encodes to SGVsbG8=; emoji and accented letters produce longer strings because they use more UTF-8 bytes.

Enable URL-safe mode when your consumer expects Base64URL — JWT segments and query strings often swap +/ for -_ and strip padding. Standard APIs and most email attachments use the default alphabet.

Copy the result with one click or download as a .txt file. For round-trip verification, paste the output into our Base64 Decoder and confirm the original text returns unchanged.

Import small .txt, .json, or .env files when you need to encode a file snippet without retyping. Clear the fields when finished on shared machines.

Browser base64 encode javascript patterns often call btoa() directly, which fails on Unicode outside Latin-1. The correct pattern encodes UTF-8 bytes first — the same approach this tool uses internally.

In Node.js: Buffer.from(text, 'utf8').toString('base64'). In Python: base64.b64encode(text.encode('utf-8')).decode('ascii'). Compare your app's output against this encoder when debugging charset mismatches.

Base64 encode js snippets in Stack Overflow answers sometimes omit UTF-8 handling. If your manual encode differs from this page for non-ASCII text, the bug is usually missing TextEncoder or encodeURIComponent wrapping.

Do not confuse Base64 with hex or URL percent-encoding. UTF-8 Encoder shows raw byte values; URL Encoder handles %XX sequences for addresses.

API payloads: embed short text blobs in JSON when binary transport is awkward. Encode here, paste into your request body, and confirm the server decodes with the same UTF-8 assumption.

Config and env files: some deployment systems expect Base64-wrapped secrets or certificates. Encode the plaintext snippet, then paste into your config manager — never treat Base64 as hiding secrets from attackers.

Data URIs and inline assets: prefix encoded image bytes with data:image/png;base64, for HTML or CSS. For full image or PDF files, use our Image to Base64 tool instead of pasting megabytes into a textarea.

Test fixtures: store expected Base64 strings in unit tests so CI asserts exact wire format, not just rendered glyphs.

URL-safe Base64 replaces + with - and / with _ and may omit trailing = padding. Enable the checkbox when encoding for JWT-style consumers or query strings that reject standard characters.

Double-encoding happens when teams encode twice by habit. If the output still looks like Base64 after one pass, decode once on the Base64 Decoder page before re-encoding.

Do not Base64 passwords or API keys to hide them from users. Base64 is reversible encoding, not protection. Use proper secret management and environment variables.

Line breaks in email-style Base64 are cosmetic whitespace — this tool strips them on decode. When encoding for RFC 2045 consumers, you may need manual line wrapping for very long strings.

TextEncoder and btoa run locally in your browser. Tokens, customer data, and internal error messages never upload to a server. Clear the textarea when finished on shared computers.

Pair with our Base64 Decoder for reverse conversion. Use Image to Base64 when you need file bytes and data URIs for <img> tags. Use Base64 to Image when you receive image payloads from APIs.

JWT middle segments are Base64URL JSON — encode or decode text here for inspection, but verify signatures in trusted libraries, not by eye alone.