Felo

Secret Code Translator Online: Alphabet, Numbers & Symbols

Encode or decode text with a fixed secret-code cipher that swaps letters a–z and A–Z in reverse order, flips digits 0–9, and pairs symbols such as ( with ) and / with \. Every character outside the table is preserved and reported, and the result arrives in a copyable block. Try it online.

What is Secret Code Translator Online: Alphabet, Numbers & Symbols?

This is a text tool that turns ordinary writing into a secret-code cipher and turns that cipher back into ordinary writing. It uses one fixed character table: lowercase letters run a→z against z→a, uppercase letters run A→Z against Z→A, digits run 0→9 against 9→0, and a defined set of symbols are swapped in pairs. The same table works in both directions, so encoding and decoding are the same operation applied twice.

It is a cipher, not a language translator. Nothing is reworded, no meaning is reversed, and no vocabulary is involved. Each character is simply replaced by its partner in the table.

Key Features

Exact fixed mapping. Letters, digits, and the paired symbols follow one published table, applied character by character, including inside words.
Encode and decode. Ask for either direction. If you do not name one, the tool encodes by default and tells you it did.
Preservation reporting. Characters outside the table — spaces, emoji, accented letters, punctuation not in the table — are kept as they are and listed in a short note.
Copyable output. The converted text arrives in its own code block so you can copy it without picking up commentary.
Table explanation on request. Ask how a specific character maps and get the exact partner.

How to Use

Paste or type your text and state the direction, for example "encode: meet me at 7" or "decode: nvv g nv zg 3". If you omit the direction, the tool encodes by default and says so.
Read the converted text in the code block. A short note below lists any characters that were left unchanged because they are not in the table.
Ask for a follow-up such as decoding the same block, mapping a single character, or re-running with a longer passage.

Example Use Cases

Secret code alphabet numbers characters substitution for a note: encode a short message for a friend and hand them the same tool to decode it.
Secret code translator for classroom puzzles: produce a cipher line for a worksheet, then decode a student's answer to check it.
Secret coded language for game props: turn a clue into coded text and keep the plain version for the game master.

A quick before-and-after: encoding Hello, World! 42 gives Svool. Dliow* 57. Decoding that result returns the original line exactly.

Tips for Best Results

Say "encode" or "decode" when your text is short or ambiguous; a single word like z could be either direction, because the table maps each character to its partner in both directions.
Keep the original text somewhere safe. The mapping is its own inverse, so re-running the output restores the input, but only if nothing was edited in between.
If you need a character that is not in the table, such as an emoji or accented letter, expect it to pass through unchanged and appear in the preservation note.

FAQ

What input does it accept?
Plain text of any length you can paste. Input is processed in one pass and is never truncated.

How accurate is the result?
The mapping is deterministic: the same input always produces the same output, and decoding an encoded line restores it exactly when every character is in the table. Characters outside the table are preserved, not guessed.

How does this tool handle unusual characters?
It states the direction it used, preserves any character that has no partner in the table, and reports those characters so you can verify the result yourself.

Does it translate languages?
No. It substitutes characters. A coded line is not a translation and carries no grammar or vocabulary of its own.