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Base64 Encoder / Decoder Online Free — PrivaTools

TL;DR: Encode text or files to Base64, or decode Base64 back to the original — runs locally, no upload.

Encode and decode Base64 online for free — convert text, files, or binary data to and from Base64 format instantly. Works entirely in your browser, no data sent anywhere.

Like the rest of the 214-tool PrivaTools suite, Base64 Encoder / Decoder is MIT-licensed and self-hostable. The public demo deletes your file as soon as the response leaves the server — verifiable in the open-source codebase on GitHub.

What Base64 Encoder / Decoder is best for

Encode and decode Base64 online for free — convert text, files, or binary data to and from Base64 format instantly. Works entirely in your browser, no data sent anywhere. Use it when you need a quick, private, no-account way to handle a file in the browser, or when you want an auditable open-source alternative to cloud converters, ad-heavy utility sites, and desktop apps. The page at /tools/base64 is designed for one clear job: upload or provide the input, choose only the options that matter, and download the result without creating an account or passing through a sales funnel.

Privacy model for Base64 Encoder / Decoder

Many non-PDF utilities run entirely in your browser; conversion or media operations that need backend libraries use the same isolated container model. Temporary input and output files are not used for analytics, model training, advertising profiles, or product telemetry. The public demo uses anonymous page-view analytics only; file bytes, extracted text, filenames, passwords, signatures, and generated results are outside that analytics path. If your organization needs stricter controls, you can self-host all 214 PrivaTools utilities and keep processing on your own infrastructure.

Quality checklist

Before running Base64 Encoder / Decoder, confirm that the source file opens correctly and that you have permission to process it. Keep the original asset, choose the smallest output that still matches your target app, and test the result before deleting source media. For sensitive material, review the downloaded result before sharing it. For large files, give the browser time to finish the download and avoid refreshing the page mid-run. If a password, damaged upload, unsupported codec, or malformed document blocks processing, PrivaTools returns a plain-language error so you can pick the next recovery step instead of guessing.

Operational details

Base64 Encoder / Decoder is intentionally narrow: it does one file task and hands the result back as a normal download. That makes the output easy to inspect, rename, archive, attach to email, or feed into another tool. If you need a repeatable workflow, save the page, bookmark a Pipeline recipe, or self-host the API so the same steps can run from internal scripts. The interface avoids accounts and cloud folders on purpose: the safest default for private files is to process only the current request, return the result, and leave long-term storage under your control.

Using Base64 Encoder / Decoder on any device

Base64 Encoder / Decoder runs in any modern browser on Windows, macOS, Linux, Android, and iOS — there is nothing to install, no extension to add, and no desktop app to keep updated. Because the interface is a single page, you can bookmark it, send the link to a colleague, or open it on a phone and get the same result you would on a laptop. There are no watermarks stamped onto your output, no sign-in wall before the download, and no paid tier that unlocks the “real” version later — the Base64 Encoder / Decoder you see is the complete tool. For teams that would rather keep everything in-house, the same endpoint ships in the MIT-licensed, self-hostable build, so you can run it behind your own firewall with identical behaviour and no outbound calls. That combination — instant in the browser for individuals, fully self-hostable for organizations — is what keeps a private file genuinely private from upload to download.

How to use the Base64 Encoder / Decoder tool on PrivaTools

  1. Choose encode or decode mode — Select whether you want to encode data to Base64 or decode a Base64 string back to its original form.
  2. Enter input — Paste text into the editor, or upload a file (image, PDF, binary — up to 500 MB). For decoding, paste the Base64 string.
  3. Get the result — The output appears instantly. Copy the Base64 string to your clipboard, or download the decoded file.

Frequently Asked Questions

Can I encode files (not just text)?

Yes. Upload any file — images, PDFs, binaries — and the tool returns the Base64-encoded string. Useful for embedding files in JSON, HTML, or CSS.

Is there a size limit for encoding?

Files up to 500 MB can be encoded. Keep in mind that Base64 output is approximately 33% larger than the original file.

What character set is used?

Standard Base64 (RFC 4648) using A-Z, a-z, 0-9, +, and /. URL-safe Base64 (replacing + and / with - and _) is also available.

Last reviewed 2026-01-22 by the PrivaTools maintainers. Source code on (MIT-licensed, self-hostable).

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