Felo

Secret Language Substitution Cipher Translator Online

Encode English into a fixed 26-symbol secret language or decode symbol text back into readable English letters. Unlike a bare two-box page, it shows the exact letter-to-symbol map, preserves punctuation and spacing, and reports any character it cannot convert. Try it online.

What is Secret Language Substitution Cipher Translator Online?

This is a text tool that turns ordinary English into a made-up symbol alphabet and turns that symbol text back into English. Each of the 26 letters has exactly one symbol partner, so the transformation is a simple, reversible substitution rather than a real language. You type a message, say whether you want to encode or decode, and get a copyable result plus a short note on anything that could not be converted.

Key Features

Two-way conversion. Encode English letters into the 26-symbol cipher, or decode cipher symbols back into English letters.
Full mapping on request. Ask for the letter-to-symbol table and get all 26 pairs listed plainly.
Careful preservation. Spaces, punctuation, digits and line breaks stay where they are; only mapped letters change.
Honest reporting. If a character has no place in the cipher, it is kept as-is and flagged rather than quietly deleted.
Round-trip check. After encoding, you can ask for the result to be decoded again to confirm it matches your original text.

How to Use

Type your English message, or paste a string of cipher symbols, into the chat. Add a word like "encode" or "decode" if the direction is not obvious.
The agent applies the fixed 26-letter map and returns the converted text in a copyable block, followed by a short note on any characters it left untouched.
Ask for the mapping table, a sample sentence in cipher, or a round-trip check whenever you want to verify the result.

Example Use Cases

Writing a secret note to a friend. Encode a short message like "meet me at noon" into symbols you can paste into a chat.
Decoding a secret language message. Paste a string of symbols someone sent you and get the English letters back.
Checking a substitution cipher by hand. Ask for the full letter-to-symbol table so you can compare it with a puzzle or worksheet.

A quick before-and-after: the word "cat" becomes "ɰɩ∠" and decoding "ɰɩ∠" returns "cat".

Tips for Best Results

Say "encode" or "decode" when your text could be read either way, such as a single letter.
Keep the original text handy if you plan to decode later; the cipher is fixed, so the same map always applies.
Ask for the mapping table first if you want to check each symbol yourself.

FAQ

What input can I give? Any plain text: words, sentences, punctuation, numbers and line breaks. Very long passages are handled in sections, and you will be told if a section was cut short.

How accurate is the result? The conversion is a fixed one-to-one letter substitution, so mapped letters are exact. Characters outside a–z, such as digits, accents or emoji, are not part of the cipher and are preserved and flagged.

How does this compare with some free text tools? Many free text tools give you two boxes and no explanation. This agent states the full mapping, reports unmapped characters, and can run a round-trip check, while still doing the same basic substitution job.

Is this a real language or a secure code? No. It is a simple substitution that anyone with the table can reverse, so it is for fun and casual notes, not for protecting sensitive information.