Base36 to file.

Base36 writes a number with the ten digits and the 26 letters, 0 to 9 then a to z, the same in either case. It is the biggest alphabet that is both alphanumeric and case-insensitive, which is why JavaScript's `toString(36)` and so many short ids use it. The tool treats the input bytes as one big number and writes that.

The bytes are read as one integer, big end first, and that integer is written in base 36 by repeated division. Each character carries about 5.17 bits, so the output is about 55% larger than the input. Leading zero bytes are kept as leading 0 characters. There is no padding.

URL shorteners, Reddit's post and comment ids, tracking and licence codes, database keys shown to people, and any place a counter has to become a short, case-insensitive string.

Yes: letters and digits only, nothing to escape, and the same string in either case.

It is for numbers and short ids. For arbitrary data it is slower than Base32 or Base64, because the whole input has to be divided as one number, and its 55% overhead sits between them. Base62 is shorter but case-sensitive; Base32 is streamable and padded.

No. Base36 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.

Paste the Base36 into the input, or drop a text file that holds it. The tool decodes the bytes, says what they look like and how many there are, and shows the image when they are one. Check the file name, which is guessed from the bytes, and press Download.

From the first bytes. Most formats start with a signature, 89 50 4E 47 for PNG, %PDF for PDF, PK for ZIP, and the tool knows the common images, documents, archives, fonts and media, and tells text from the rest. It is a guess for the file name only; if you know what the bytes are, rename the file and it downloads under that name.

Usually the Base36 was cut short or carries something extra. Copy the whole value, including its end; leave out quotes and commas from the surrounding code. If the status line says the bytes look like text when you expected an image, the value wasn't the file's Base36 to begin with.

Nothing leaves your browser. The text 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 "Base36 to file" tool is free and opens without a sign-in, an account or an install.

Nothing. The "Base36 to file" tool holds your input in the page's memory, so closing or reloading the tab clears it, and it saves nothing in this browser.

Yes: you can rename it before downloading. The default name is decoded plus the extension the format suggests, such as decoded.png.

When the bytes start like a PNG, JPEG, GIF, WebP, AVIF, ICO, BMP or SVG image, the page shows a preview before you download it. Other types show their size and the name of the format they start like.

The decoder takes digits and letters in either case. Base36 treats the text as one number, so the tool takes up to 512 KB of data at once.

Closest to the "Base36 to file" tool: File to Base36, Base36 decoder, Base36 encoder, Base62 to file. Each opens on its own page, free and in the browser.

The "Base36 to file" 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.