Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 back to text — UTF-8 safe, instant, in your browser.

Runs entirely in your browser — nothing is sent to a server.

How to use the Base64 Encoder / Decoder

  1. Pick a mode. Choose encode (text → Base64) or decode (Base64 → text).
  2. Paste your input. Type or paste the text or Base64 string.
  3. Copy the result. Hit the button and copy the output to your clipboard.

Why use our Base64 Encoder / Decoder

Encode and decode. Switch modes to turn text into Base64 or convert Base64 back to readable text.
UTF-8 safe. Handles emoji and accented characters correctly, unlike a plain btoa().
Private & instant. Everything is computed locally — your data never touches a server.

Free to use — premium coming soon

FREE
  • Encode & decode
  • UTF-8 support
  • One-click copy
  • 100% private
PREMIUM
  • Remove ads
  • File-to-Base64 & data URLs
  • Bulk conversion

About the Base64 Encoder / Decoder

Base64 is a binary-to-text encoding scheme that represents arbitrary data using only 64 printable ASCII characters: the letters A-Z and a-z, the digits 0-9, and the symbols + and /, with = used as padding. It exists because many systems and protocols were designed to move plain text safely, not raw bytes. This encoder takes whatever you type or paste, treats it as UTF-8 bytes, and produces a Base64 string that you can drop into email, JSON, XML, HTML attributes, or a URL without worrying about characters being mangled in transit.

Reach for Base64 whenever binary or text data has to survive a text-only channel intact. Classic cases include email attachments (the MIME standard relies on Base64 because original SMTP only carried 7-bit ASCII), embedding small images or fonts directly in CSS and HTML as data: URIs, stashing tokens or small payloads inside JSON and JWTs, and passing configuration through environment variables or query strings. The decoder direction is just as common: you paste a Base64 blob from a config file, an API response, or a log line and instantly read back the original text.

Mechanically, Base64 reads your input three bytes at a time. Three bytes make 24 bits, which split cleanly into four 6-bit groups, and each group (a value from 0 to 63) maps to one Base64 character. When the input length is not a multiple of three, the final group is zero-padded and one or two = signs are appended so decoders know how many real bytes the last block held. Because four output characters carry only three input bytes, Base64 grows the data by roughly 33%, which is why it is an encoding for transport, never a compression step.

This tool runs entirely in your browser using the native encoder with proper UTF-8 handling, so emoji and non-Latin scripts round-trip correctly rather than throwing the classic "characters outside the Latin1 range" error that plain btoa() produces. Nothing you enter is uploaded or logged. One important note on accuracy and safety: Base64 is not encryption and provides no security at all. Anyone can decode it in a second, so never treat a Base64 string as a way to hide passwords, keys, or private data.

Frequently asked questions

Is Base64 a form of encryption?

No. Base64 is a reversible encoding, not encryption, and offers zero confidentiality. Anyone with the string can decode it instantly, so never use it to protect passwords, API keys, or sensitive information.

Why is my Base64 output longer than the original text?

Base64 turns every 3 bytes of input into 4 output characters, so the result is about 33% larger. That overhead is the trade-off for making binary-safe data fit through text-only channels like email and JSON.

Does this tool handle emoji and accented or non-English characters?

Yes. It encodes your input as UTF-8 first, so emoji, accents, and scripts like Arabic, Chinese, or Cyrillic encode and decode correctly without the Latin1 range errors that browsers throw when characters fall outside single-byte ASCII.

What do the = signs at the end of a Base64 string mean?

They are padding. When the input length is not a multiple of three bytes, the encoder adds one or two = characters so the decoder knows how many real bytes the final block contained. A correct string is always a multiple of four characters.

What is the difference between standard Base64 and Base64URL?

Standard Base64 uses + and / which can break inside URLs and filenames. Base64URL replaces them with - and _ (and often drops padding) so the string is safe to put in links, query parameters, and JWTs.

From our blog

How to Make a QR Code That Actually Scans Every Time

By the Super Simple Digital Tools Team · Updated June 2026

Generating a QR code takes a second, but making one that scans reliably on a crumpled flyer or a sun-faded window decal takes a little thought. The pattern you see is not random art: it includes fixed position markers in three corners, timing lines, and Reed-Solomon error-correction data that lets a scanner rebuild missing pieces. Understanding those parts helps you avoid the most common failure, a code that looks fine on screen but refuses to scan once it is printed small or partially obscured.

Start with the content, because it determines how dense the grid becomes. A QR code stores data in numeric, alphanumeric, or byte mode, and shorter strings use fewer modules. A long tracking URL packed with parameters creates a busy, fine-grained pattern that struggles at small sizes, while a short link produces large, forgiving modules. If your destination URL is long, shorten it first so the printed code stays readable from a normal scanning distance.

Error correction is the next lever. The four levels, L, M, Q, and H, recover roughly 7, 15, 25, and up to 30 percent of a damaged code. Level H is worth choosing for anything that will be printed outdoors, placed on a curved bottle, or stamped onto a textured surface, since it tolerates scuffs and partial coverage. The cost is a denser pattern, so pair a high error-correction level with short content to keep the modules large.

Size and contrast finish the job. Industry guidance suggests keeping a printed code at least around two by two centimetres, and larger if it will be scanned from a distance, with a clear quiet-zone margin of blank space around all four sides. Keep the code dark on a light background; inverting the colours or using a low-contrast pairing is the quickest way to make a phone camera give up. Always test the final printed code with more than one device before mass-producing it.

Finally, decide whether static is the right model for you. Because this tool builds static codes that carry no redirect, they never expire and report no scan data, which is ideal for Wi-Fi credentials, contact cards, and permanent signage. If you genuinely need to change the destination after printing or measure scan counts, you would want a dynamic code from a service that hosts the redirect, accepting that it ties your code to that provider remaining online.

  • Shorten long URLs before encoding so the pattern stays coarse and scans easily at small print sizes.
  • Choose error-correction level H for outdoor, curved, or textured surfaces where the code may get scuffed or partly covered.
  • Leave a clear quiet-zone margin of blank space around all four sides; cropping too tight breaks scanning.
  • Print at roughly two centimetres or more, keep it dark on light, and test on two different phones before going to production.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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