File to Hex.

Hexadecimal, Base16, writes every byte as two digits from 0 to 9 and A to F. Each digit is four bits, so the mapping is direct: no grouping, no padding, no arithmetic. It is the way bytes are shown in debuggers, hash digests, colour values and memory dumps.

A byte is split into two nibbles of four bits, each written as one of 16 digits: 0x48 is 01001000, the H of ASCII, written 48. The output is exactly twice the size of the input. Upper and lower case mean the same thing; the decoder reads both, with or without spaces or 0x prefixes.

Hash digests (a SHA-256 is 64 hex digits), CSS colours (#FF5733), MAC addresses, memory addresses, cryptographic keys and IVs, file signatures (a PNG starts 89 50 4E 47), and every hex dump a developer reads.

Yes: digits and letters only, nothing to escape.

Twice the size of the bytes, the worst of the practical encodings, and the most readable: a byte is two digits and you can see them. Use it to show bytes to a person; use Base64 to carry them.

No. Hex is an encoding, not encryption: it changes how bytes are written, not who can read them, and anyone can decode it with no key. Encrypt first (AES, age, a library's sealed box) when the content needs protecting, then encode the ciphertext if it has to travel as text.

Drop the file onto the input or choose it with the button. Its bytes are encoded in your browser and the Hex appears in the result pane, with the size it grew to. Copy it, or download it as a text file.

Any file the browser can hold in memory works; a few hundred megabytes is fine, and the result is twice the size.

Whatever needs the bytes as text: a byte array in source code, a signature check, or a dump to compare against another. Hex is safe in a URL as it is, and it is twice the size than the file, so it is for carrying bytes through text, not for storing them.

Nothing leaves your browser. The file is read into memory on your machine and the encoding is computed there, in plain JavaScript; the page makes no request with it. Load the page, go offline and it keeps working.

No. The "File to Hex" tool is free and opens without a sign-in, an account or an install.

Nothing. The "File to Hex" tool holds your input in the page's memory, so closing or reloading the tab clears it, and it saves nothing in this browser.

Any file the browser can open. The bytes are read in your browser and encoded as Hex; the result can be copied or downloaded as hex-encoded.txt.

Hex output is 2 characters per byte, so twice the size, and the status line under the result shows the bytes in, the characters out and the percentage.

Use the Hex to file page: it decodes Hex back to the original bytes, and names the download after the file type it recognises.

Yes, the same choices as the text encoder: Case, and spacing between bytes.

Closest to the "File to Hex" tool: Hex to file, Hex encoder, Hex decoder, File to Binary. Each opens on its own page, free and in the browser.

The "File to Hex" tool is one of 32 in its group. The group's page, /tools/encoding, lists them all.

The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.