Base64 Encoder & Decoder

Encode text or files to Base64 and back

🔒 100% ブラウザ内🆓 ずっと無料⚡ サインアップ不要
注意: 下記のツールインターフェースは現時点で英語のみに対応しています。UI の翻訳は順次進めています。 このツールを英語で見る →

使い方

  1. 1
    Paste text or drop a file

    Type or paste text, or upload any file up to your browser's memory limit.

  2. 2
    Pick encode or decode

    Toggle standard or URL-safe Base64 variants.

  3. 3
    Copy or download

    Copy the output or download the decoded file.

Base64 Encoder & Decoder について

Free online Base64 encoder and decoder. Encode any text or file to Base64 (standard or URL-safe), or decode Base64 back to its original form. Handles Unicode, binary files, and data URIs - all in your browser. 712 Tools の Base64 Encoder & Decoder はモダンな JavaScript API を使って完全にブラウザ内で動作します - サーバーがあなたのデータを見ることは一切ありません。つまり、即時の結果、完全なプライバシー、アップロード制限なしです。

デバッグ、簡単な確認、あるいは本番のインシデント対応まで - このツールは何度でも無料で使えます。ウォーターマークなし、サインアップなし、ツール内広告なし。

よくある質問

What's URL-safe Base64?

It replaces + with - and / with _ so the string can appear in URLs without percent-encoding. Padding = characters are sometimes stripped too.

Does it handle Unicode?

Yes. Text is UTF-8 encoded before Base64 conversion, so emoji and non-ASCII characters round-trip correctly.

Is my file uploaded?

Never. All encoding and decoding runs in your browser via native APIs. Neither text nor file bytes leave your device.

What's the file size limit?

Bound by your browser's memory. Files under 50 MB typically encode instantly; larger files may pause briefly.

続きを読む

4 分で読了

QR code formats: encoding Wi-Fi, contacts, calendars, and payments

A QR code is just text - but the right prefix turns it into a Wi-Fi login, a saved contact, or a calendar invite. Here are the standard formats worth knowing.

5 分で読了

How to generate a strong password (and why length beats symbols)

The math behind password strength, the myth of the special-character requirement, and how modern password managers changed the whole equation.

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