# An AI coding assistant that explains its fixes

By the SelGPT team. Updated October 1, 2026. Source: https://selgpt.app/ai-for-coding

Paste an error, a function or a whole file and ask what you need. SelGPT writes code, finds bugs and explains them, in the languages and frameworks you already use.

> SelGPT works as an AI coding assistant in your browser. Use Sel-Altair, its coding model, to write functions, explain error messages, review code and debug, and switch to Sel-Sirius for hard architecture or review work. Every model can search the web for current documentation. Both are included in SelGPT Plus.

## What you can ask it

- Write a function, script, query or component from a plain description.
- Explain an error message or stack trace and suggest a fix.
- Review code for bugs, edge cases, security issues and readability.
- Refactor code, add types or translate it to another language.
- Look up the current documentation for a library before answering.

## Which model to use

- [Sel-Altair](https://selgpt.app/models/sel-altair): everyday coding. Fast, and built for writing, reviewing and debugging code.
- [Sel-Sirius](https://selgpt.app/models/sel-sirius): the hardest problems, such as system design, tricky bugs and careful code review.
- [Sel-Vega](https://selgpt.app/models/sel-vega): quick questions about syntax or a command, unlimited on paid plans.

You can switch models in the middle of a conversation and keep everything you have shared so far.

## Try asking

- “Why does this React effect run twice, and how do I fix it?”
- “Write a SQL query that finds customers who ordered twice within 30 days.”
- “Review this function and list anything that could break in production.”

[See plans](https://selgpt.app/pricing)

## Questions

### Which SelGPT model is best for coding?

Sel-Altair for most coding work, and Sel-Sirius for the hardest problems such as architecture decisions and careful reviews. Both are included in Plus and Pro.

### Can SelGPT read my code files?

Yes. Paste code into the chat or upload files, and ask about them. Uploads are limited per day on each plan; see the pricing page for the numbers.

### Is the coding model free?

The Free plan includes Sel-Vega, which handles quick coding questions. Sel-Altair and Sel-Sirius come with Plus, from $9.99 a month billed yearly.

## Related

- [Sel-Altair](https://selgpt.app/models/sel-altair): Sel-Altair is SelGPT’s coding model: it writes, reviews and debugs code across the languages you work in, and answers fast. Included in Plus and Pro.
- [Sel-Sirius](https://selgpt.app/models/sel-sirius): Sel-Sirius runs on the AI model ranked #1 on the Artificial Analysis Intelligence Index, included in SelGPT Plus from $9.99 a month billed yearly.
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- [AI for research](https://selgpt.app/ai-for-research): Research with SelGPT: it searches the web, pulls several sources together, compares them and shows where every fact came from.
- [AI for students](https://selgpt.app/ai-for-students): Use SelGPT to understand hard topics, check your working, summarise readings and plan revision. Free to start, with no ads.
- [AI for math](https://selgpt.app/ai-for-math): Solve and understand maths problems step by step with SelGPT’s reasoning model, from algebra and statistics to proofs and word problems.