Code Comment Generator
Add clear, helpful comments to your code in seconds
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When did you last write a docblock before the code shipped? Could a new contractor open your invoicing class tomorrow and know what it expects? Code Comment Generator reads the code you paste in and writes the comments back into it, so the file explains itself to the next person who opens it.
Short answer: Code Comment Generator is a free AI tool on EizTools that adds inline comments and doc comments to code you paste in. Choose the language, the audience and the comment format, then generate the annotated version.
What is Code Comment Generator?
The prompt box asks for one thing: paste the code you want explained. From there Code Comment Generator writes the annotations. Set Output Format to Inline Comments and the notes sit beside the lines they describe. Set it to Doc Comment and you get the header block your language expects, the one your IDE shows on hover and your documentation tool picks up.
How Does Code Comment Generator Work?
Paste the code, pick an AI model from the selector, open the advanced options, then press Generate. The annotated version lands in the output card with a word count and a reading estimate. Copy it, or download it as TXT, Word or HTML. The activity history panel keeps the last few runs, so you can annotate three files and come back to the first.
Four dropdowns do the shaping, and every one starts on None, which hands the decision to the model.
| Option | What it controls | Try this first |
|---|---|---|
| Output Format | The kind of comment written | Doc Comment for public methods, Inline Comments for tricky logic |
| Audience | Who the comments are written for | Team, since most comments are read by colleagues |
| Explanation Depth | How much each comment says | High-Level, so the file does not double in size |
| Language | The comment syntax used | Auto-Detect, or name it for short snippets |
Toggles follow for Line-by-Line, Add Examples, Add Summary and Note Edge Cases. A Depth slider and a Custom Instructions box handle the rest, and that box is where your team's docblock convention goes.
Where It Fits In A Normal Working Day
Think of a solo developer handing a Laravel invoicing class to a new contractor. The class works, but the only comment in it says "fix later".
- Paste the class into the prompt box.
- Set Output Format to Doc Comment and Audience to Team.
- Generate, then read the comments against the code.
- Fix anything the model guessed wrong, especially business rules it could not see.
- Commit the annotated file, then run your documentation tool over it.
The review step is the point. You go from writing comments to checking them, which is far less dull.
Files That Are Worth Annotating First
- The one nobody wants to touch. Old code with side effects and no notes.
- Public methods and shared helpers. Anything other people call deserves a doc comment.
- Code you wrote at speed. A hotfix from three months ago is now somebody else's problem.
- Handover work. Freelance projects, contractor pickups and anything leaving your machine for good.
Comments That Help Versus Comments In The Way
Bad comments repeat the code. Good ones explain the decision behind it. Keep Explanation Depth modest and delete anything that just restates a line.
Tip Never let a generated comment describe a business rule you have not checked. If it says a fee applies after thirty days, confirm the number in the code before you commit that line.
What works well
- Turns undocumented files into readable ones in a single pass
- Matches the doc comment style of the language you select
- Free, with no account, no install and no editor plugin
What to watch for
- It sees only the pasted snippet, never the rest of your repository
- Deep settings can produce more comment than code
- Anything it infers about intent needs a human to confirm it
EizTools is free to use, with a separate AI workspace for each job rather than one general chat box. No account, no credit counter, no paid tier, and the AI model is yours to pick before each run. If the class you are annotating is mostly raw queries, SQL Generator can draft those from a plain description first.
Frequently Asked Questions
Does Code Comment Generator change my code?
It returns your code with comments added, and the logic should come back untouched. Still read the output before pasting it over the original, and let version control show you the difference.
Which comment styles can it write?
Output Format offers Inline Comments and Doc Comment, plus Plain Explanation, Step-by-Step and Summary when you want prose instead. The syntax follows the language you select.
Can it follow our team standard?
Yes, through the Custom Instructions box. Describe your docblock rules, tag order or line length in a sentence or two and the generated comments follow them.
How much code can I paste at once?
One class or one file gives the best results. Very large pastes get thinner comments, so split them and run the important sections separately.
Documentation slips because writing it feels like work you already did. Code Comment Generator moves that job from writing to reviewing, which is the version people finish. Paste the file you have been avoiding into the box above, pick Doc Comment, and see how much comes back ready to commit. More of the set sits in Coding Tools.
Sabir Bepari
Founder of EizTools and a passionate AI enthusiast dedicated to building practical, user-friendly AI tools that simplify everyday tasks.
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