AI code explainer
Explain unfamiliar code, config or tool output block by block, or line by line.
Your key stays in your browser.It goes straight to the provider, never to our servers, and we neither log nor keep it. Use a dedicated key with a spending cap, and delete it in the provider's dashboard when you are done.
Input
Result
The result will appear here.Inherited a function nobody documented, a regex you cannot read, or a Dockerfile with twenty flags? Paste it and get an explanation of what it does, how it gets there, and what might surprise you. The prompt is adapted from the explain_code pattern in danielmiessler/Fabric, the 40k-star prompt collection: it recognises whether you pasted code, configuration or security-tool output and answers with the matching section, plus a direct answer if you include a question alongside the code.
How it works
- Every line of a snippet is numbered before sending, so the explanation can point at L14–L20 instead of paraphrasing the code back to you.
- Overview explains functions and blocks; Line by line walks through the code in order, quoting each line — slower, but best for learning a language.
- Choose the answer language independently of the code: English source code can be explained in Chinese, Japanese, German or French.
Where your data goes
With your own key, what you type and the key go from your browser straight to the provider you choose; neither passes through Hysen Labs. In hosted mode, your text goes through our server to our provider (DeepSeek) and is billed in credits; we keep the token counts and cost of each run for billing, never the text itself or the answer. How the provider handles the text is governed by its own privacy policy.
This tool handles keys and credentials, so nothing about a run is saved, not even to your own history.
About your API key
We do not collect, store or leak your key: it lives only in this page's memory (unless you tick “remember in this tab”) and is gone when you close it. Still, treat any key you have pasted into a web page with care — create a dedicated key with a spending cap for use here, and delete or rotate it in your provider's dashboard when you are done.
What it costs
This tool is free, with no sign-in and no points.
Common questions
- Is my code sent anywhere besides the AI provider?
- No. The request runs from your browser to the provider you select, with your key; nothing passes through our server. For proprietary code, pick a provider whose data policy you accept and use a key created just for this, with a low limit.
- Can I ask a specific question about the code?
- Yes — write the question above or below the snippet, for example "why does this return None for '1h 30'?". The prompt answers it in its own section, and "Same as input" makes the answer follow the language of your question.
- How reliable is the explanation?
- Good for reading intent and spotting non-obvious logic, but the model sees only what you paste. When behaviour depends on an imported function or a config value it cannot see, it is told to say so rather than guess — verify anything important by running the code.
The open-source behind it
This tool's prompt is adapted from danielmiessler/Fabric (MIT) and runs on the model you choose. To use the same capability from the command line or inside your own program, start with that project.
danielmiessler/FabricAlso known as
- ai code explainer
- explain code online
- what does this code do
- code explanation ai
- explain regex code