Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to plain text — entirely in your browser. Your input never leaves the page.
- Runs in your browser
- No upload, no tracking
- Free forever
How it works
Base64 encoding represents arbitrary data as a string of 64 printable ASCII characters, making it safe to embed binary or Unicode content in text-based formats like JSON, HTTP headers, data URIs and email. A Base64 encoder/decoder converts plain text to that representation and back again. This tool UTF-8 encodes first so emoji and any Unicode work correctly, and it runs entirely in your browser — built by JusDB, a managed database operations team.
- 1
Choose a direction
Use the toggle to switch between Encode (plain text → Base64) and Decode (Base64 → plain text). The panel labels update to match.
- 2
Type or paste your input
Enter text on the left and the result appears live on the right as you type — no button to press.
- 3
Handle errors
If you try to decode a string that isn't valid Base64, an inline message explains the problem instead of producing garbage output.
- 4
Copy or clear
Copy the output with one click, or Clear to reset both panels. Encoding and decoding happen locally — nothing is uploaded.
Frequently asked questions
- What is Base64 encoding?
- Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters. It is commonly used to transmit binary data over text-based protocols like HTTP and email.
- Is my data safe when using this tool?
- Yes. All encoding and decoding happens entirely in your browser using JavaScript. Your input is never uploaded to JusDB or any server.
- Why does my Base64 string end with == or =?
- Base64 encodes data in 3-byte blocks. If the input is not divisible by 3, padding characters (=) are added to make the output a multiple of 4 characters.
- Can Base64 handle Unicode or emoji?
- Yes. This tool first UTF-8 encodes the input before Base64 encoding, so it correctly handles any Unicode character including emoji.
- What is the difference between Base64 and encryption?
- Base64 is encoding, not encryption. Anyone with a Base64 decoder can read the original content. Do not use Base64 to protect sensitive data — use proper encryption for that.
Understanding Base64: what it solves and where it bites
Base64 exists to move binary data through channels that were only ever designed to carry text. Plenty of transports — older email relays, JSON payloads, HTTP headers, YAML config files — choke on raw bytes, control characters or anything outside a narrow printable range. By mapping every 3 bytes onto 4 characters drawn from a fixed 64-symbol alphabet, Base64 produces output that survives those text-only pipelines intact, then decodes back to the exact original bytes on the other side.
Where you'll actually meet it
The classic uses are all about embedding bytes inside text. Data URIs inline a PNG or SVG directly in HTML or CSS (data:image/png;base64,...) so a small asset ships without a separate request. Email attachments are Base64-wrapped under MIME because SMTP historically assumed 7-bit ASCII. TLS certificates and keys travel as Base64 inside PEM blocks. And the header and payload segments of a JSON Web Token are Base64URL-encoded JSON — which is why a JWT looks like gibberish until you decode each part.
The size cost is real
Because 3 bytes become 4 characters, Base64 inflates payload size by roughly 33% before any padding. That overhead is usually worth it for small assets, but for large files it can hurt: a 1 MB image becomes about 1.37 MB of text, and inlining it as a data URI also defeats browser caching. As a rule, inline tiny assets and keep large binaries as separate, cacheable files.
Encoding is not encryption
This is the single most important caveat. Base64 is fully reversible by anyone — there is no key and no secret. Dropping a password, API token or connection string into Base64 hides it from nobody; it is trivially decoded. If you need to protect a value, reach for real encryption, and if you only need to verify integrity, use a cryptographic hash instead. Treat anything you Base64-encode as effectively public.
Standard vs URL-safe, and UTF-8 gotchas
Standard Base64 uses + and / as its last two symbols and pads with =. Those characters are unsafe in URLs and filenames, so the URL-safe variant swaps them for - and _ and often drops padding entirely — that is the flavor JWTs use. The two are not interchangeable: feeding a URL-safe string to a strict standard decoder fails. Watch your input type too. Base64 operates on bytes, so text must first be turned into bytes via an encoding, almost always UTF-8. Encode as Latin-1 on one side and decode as UTF-8 on the other and any non-ASCII character — accents, CJK, emoji — comes back mangled.
Everything here runs client-side: your text is converted in the browser and never sent to a server, so it is safe to paste config snippets or token segments while you inspect them. When in doubt about which alphabet you are looking at, scan for - and _ (URL-safe) versus + and / (standard) before decoding.