Alphabet checker
Quickly test a substitution alphabet on a text.
Enter a 26-letter substitution line and immediately see how it transforms a text, with _ for letters that are still unmapped.
Alphabet
Enter the substitution alphabet.
Source text
0 source char.
Result
Add source text.
Quick explanation
Paste or type the substitution alphabet below the plain alphabet, then add source text. The conversion updates automatically while preserving case, spaces, digits, and punctuation.
Try this too
Need to generate a complete alphabet?
Use Random alphabet to quickly create a shuffled substitution alphabet containing all 26 letters.
Additional information
What is this alphabet checker for?
This checker is the most direct tool for testing a substitution key that is already known or nearly complete. The plain alphabet stays fixed: ABCDEFGHIJKLMNOPQRSTUVWXYZ. You simply enter the 26 substitution letters, then the result appears live.
Fast checking
If a letter does not have a mapping yet, it becomes _ in the result. This makes gaps in your alphabet immediately visible.
Text structure preserved
Case, spaces, digits, and punctuation are preserved. You can test a full sentence without losing its structure.
Single input line
The tool avoids unnecessary options: one alphabet line, one source text, one result. It is designed for quickly checking a hypothesis.
Which substitution tool should you choose?
| Tool | Main strength | Best use |
|---|---|---|
| Alphabet checker | The most minimal one. | Use it to quickly test a 26-letter line you have found, copied, or received. |
| Random alphabet | The most powerful for generating and solving. | Use it to generate an encoding alphabet, fill a table manually, or work calmly through a coded message. |
| Simple substitution | The most ergonomic for building a key manually. | Use it to place letter tiles one by one, avoid duplicates, and correct a substitution easily. |
Practical tip
Use Random alphabet if you want to generate a key or explore several guesses. Use Simple substitution if you prefer handling letters visually. Come back here when you have an alphabet line to check quickly.
Limits and reuse
AppErgo tools are provided free of charge for practical and informational purposes. Although care is taken in their design, a result may be incomplete, unexpected or incorrect. Before relying on a result for any important use, check it using an appropriate method.
To report a bug in the tool, you can use the dedicated bug report form.
Results produced by AppErgo tools may be copied and reused freely. When publicly reusing a result, a method or an AppErgo page, a link to the relevant page is appreciated.
Unless otherwise stated, AppErgo texts, images, visual elements, scripts, templates and internal components remain the property of AppErgo.
For any other request, you can contact the webmaster.