By AnthropicSan Francisco, United States3 products across 7 categories
Built for this. Reads long files and whole error traces without losing the thread, which makes it good at explaining unfamiliar code and debugging in a chat window.
Free plan
Yes
Free tier with daily caps
Month to month
$20/mo
Pro
Billed yearly
$17/mo
$200 a year, Pro plan −15%
Watch out: The chat window has no access to your project. For multi-file work you need the agent below or a dedicated editor.
By Google DeepMindLondon, United Kingdom6 products across 6 categories
Strong fit. Unusually generous free tier for individuals, and it plugs into standard IDEs rather than requiring a new one.
Free plan
Yes
Free for individuals, unusually generous
Month to month
$22.80/mo
Standard
Billed yearly
—
No yearly price published
Watch out: Less capable at whole-repository reasoning than the purpose-built agents. It is also reachable through the Google Developer Program, which is a separate membership with its own terms rather than a tier on this ladder.
By AmazonSeattle, United States2 products across 1 category
Strong fit. The assistant that already has your AWS account in context, which makes it the practical choice for questions about infrastructure you actually run.
Free plan
Yes
Amazon Q Developer free tier with limited agentic requests a month, the latest Claude models
Month to month
$19/mo
Amazon Q Developer Pro
Billed yearly
—
No yearly price published
Watch out: Sold and billed through AWS on top of your cloud bill. Q Developer Pro is $19 a user a month; Q Business is a separate product at $3 (Lite) or $20 (Pro) a user a month, with a 60-day trial for up to 50 users.
All plans (4)
Plan
Price
What you get
Free
$0
Amazon Q Developer free tier with limited agentic requests a month, the latest Claude models, and use in the IDE or CLI
Amazon Q Developer Pro
$19/mo
Amazon Q Business Lite
$3/mo
60-day free trial for up to 50 users per application
Amazon Q Business Pro
$20/mo
60-day free trial for up to 50 users per application
By GitHubSan Francisco, United States2 products across 1 category
Built for this. The default, and the one already wired into the editor and the pull request your team uses. A free tier now covers light use.
Free plan
Yes
2,000 completions a month
Month to month
$10/mo
Pro
Billed yearly
—
No yearly price published
Watch out: Suggestions are strongest on common patterns and weakest exactly where your codebase is unusual. Pro and above bundle a monthly credit allowance, so premium-model work is metered on top of the seat.
Two things separate these and both are on every card.
Fit
Whether a tool is built for this job, a strong fit for it, or
able to do it without that being its focus.
Free plan
Whether there is a tier you can keep using rather than a
trial that expires.
The order
Fit first, then a free plan, then alphabetical. There is
no score, no weighting we decline to publish, and nothing on this site a company can buy.
Questions
What is the best ai for debugging?
There is no single answer, which is why this page lists 9 rather than one: Claude, ChatGPT, Cursor, Claude Code, Gemini Code Assist, CodeRabbit, Amazon Q, GitHub Copilot, JetBrains AI. 6 of them are built for this kind of work rather than able to do it. Start with a free one.
Which of these have a free plan?
8 of the 9: Claude, ChatGPT, Cursor, Gemini Code Assist, CodeRabbit, Amazon Q, GitHub Copilot, JetBrains AI. Free means a real free tier you can keep using, not a trial that expires.
How was this list chosen?
By hand, from the 750 products this site tracks, and it is checked against the catalogue on every build — a product renamed or removed breaks the build rather than quietly disappearing from here. Nothing on this site can be paid for: no listing, no position, no wording.
