Claude 3.7 and Claude 4 in Cursor: Setup and Differences

Anthropic's Claude models have become the backbone of serious Cursor users. When Claude 3.7 launched, it brought meaningful improvements. When Claude 4 (Sonnet and Opus variants) followed, the gap between Claude and competing models in Cursor widened further. This guide covers what's new in each version, how to access them, what they cost, and whether upgrading makes sense for your workflow.

Claude 3.7: The Foundation

Claude 3.7 Sonnet arrived as a significant upgrade over Claude 3.5 Sonnet, which had already established itself as the go-to model for coding in Cursor.

What Changed in 3.7

1. Improved code reasoning

Claude 3.7 demonstrated better step-by-step reasoning for complex coding tasks. Where 3.5 might generate plausible-looking code that missed edge cases, 3.7 showed more careful analysis:

Example improvement (based on community reports):

Claude 3.5: Generated a sorting function that worked for 90% of cases
            but failed on empty arrays and duplicate keys.

Claude 3.7: Generated the same function with explicit null checks,
            duplicate handling, and a note about time complexity.

2. Better instruction following

Users reported that 3.7 was less likely to hallucinate features or ignore constraints. When told "do not add external dependencies," 3.7 complied more reliably than 3.5.

3. Faster response times

While not dramatically faster, 3.7 showed more consistent latency. The variance between fast and slow responses decreased, making the coding experience feel smoother.

4. Enhanced context utilization

With the same 200K token context window, 3.7 made better use of the available context. It referenced earlier parts of long conversations more accurately and maintained coherence across multi-file Composer sessions.

Claude 3.7 in Cursor: How It Worked

When 3.7 launched in Cursor, it was available as:

• Claude 3.7 Sonnet -- the standard model for chat and Composer
• Claude 3.7 Sonnet MAX -- a higher-throughput variant (later phased out)

Access required a Pro or Business subscription. Free-tier users could not select 3.7.

Claude 4: The Current Generation

Claude 4 represents Anthropic's latest leap. In Cursor, you will encounter two variants:

Variant	Best For	Speed	Cost
Claude 4 Sonnet	Daily coding, refactoring, debugging	Fast	Medium
Claude 4 Opus	Complex architecture, deep reasoning	Slower	High

What's New in Claude 4

1. Significantly better multi-file reasoning

Claude 4 Sonnet handles multi-file refactoring with fewer errors than 3.7. In Cursor's Composer, this means:

• More accurate cross-file references
• Better understanding of import/export relationships
• Fewer "I forgot to update this file" mistakes

2. Improved handling of large codebases

For developers working on monorepos or large projects, Claude 4 maintains coherence better when analyzing hundreds of files. The context window is still 200K tokens, but the model uses it more effectively.

3. More natural code style

Claude 4 generates code that feels more idiomatic. Python looks like Python written by a Python expert. TypeScript follows community conventions more closely. Rust code respects ownership patterns without excessive cloning.

4. Reduced hallucination of APIs

A common frustration with earlier models was inventing function names or parameters that do not exist. Claude 4 shows measurable improvement here, though it is not perfect.

Community test (informal, 50 prompts):
- Claude 3.7: 12% of suggestions contained hallucinated APIs
- Claude 4 Sonnet: 6% of suggestions contained hallucinated APIs
- Claude 4 Opus: 3% of suggestions contained hallucinated APIs

5. Better at saying "I don't know"

When faced with ambiguous requirements or incomplete context, Claude 4 is more likely to ask clarifying questions rather than guessing. This saves debugging time later.

How to Select Claude 3.7 or Claude 4 in Cursor

Step-by-Step Selection

1. Open the Chat panel (Ctrl+L / Cmd+L)
2. Click the model dropdown at the top of the chat input
3. Select your preferred Claude variant:
   • Claude 4 Sonnet
   • Claude 4 Opus
   • Claude 3.7 Sonnet (if still available)

Model dropdown location:
[Chat Panel] > [Top of input area] > [Dropdown showing current model]

Setting a Default Model

To make Claude 4 your default for all new chats:

1. Open Settings (Ctrl+, / Cmd+,)
2. Search for "Default Model"
3. Select "Claude 4 Sonnet" from the dropdown

// settings.json
{
  "cursor.defaultModel": "claude-4-sonnet"
}

Tab Model Selection

You can also use Claude models for Cursor Tab (autocomplete):

1. Open Settings
2. Search for "Tab Model"
3. Select "Claude 4 Sonnet"

Tab Model Latency

Using Claude 4 for Tab completions increases latency significantly compared to Cheetah (Cursor's default Tab model). Only switch if you prioritize completion quality over speed.

Pricing Changes

Claude 4's arrival brought pricing adjustments in Cursor. Understanding these is critical for managing your subscription costs.

Request Types in Cursor

Cursor categorizes requests into two tiers:

Tier	Models Included	Pro Plan Allowance
Fast requests	GPT-4o mini, Cheetah	500/month
Premium requests	Claude 4 Sonnet, Claude 4 Opus, GPT-4o, o3-mini	500/month

Claude 4 Request Costs

Model	Requests per Pro Plan	Notes
Claude 4 Sonnet	~500/month	Uses 1 premium request each
Claude 4 Opus	~150-200/month	Uses premium requests at a higher rate
Claude 3.7 Sonnet	~500/month	If still available

Opus Consumption

Claude 4 Opus consumes premium requests faster than Sonnet. One user reported exhausting their entire monthly Pro allocation in about 2-3 days of heavy Opus usage. Use Opus sparingly.

Business Plan Differences

The Business plan ($40/user/month) includes:

Feature	Pro ($20/mo)	Business ($40/mo)
Premium requests	500/mo	1000/mo
Claude 4 Opus	Yes	Yes
Claude 4 Sonnet	Yes	Yes
Background agents	Yes	Yes
Admin controls	No	Yes

For teams where multiple developers use Claude 4 heavily, the Business plan's doubled request limit often pays for itself.

Claude Max: The Heavy User Alternative

If you hit Cursor's premium request caps regularly, consider a Claude Max subscription directly from Anthropic:

Plan	Price	Includes
Claude Pro	$20/mo	Standard Anthropic access
Claude Max (Tier 1)	$100/mo	5x usage vs Pro
Claude Max (Tier 2)	$200/mo	10x usage vs Pro

With Claude Max, you bring your own API key into Cursor:

// Cursor Settings > Models > Anthropic API Key
{
  "anthropic.apiKey": "sk-ant-api03-..."
}

This bypasses Cursor's per-request limits entirely. You pay Anthropic directly for usage.

When to Get Claude Max

Consider Claude Max if you use Claude 4 Opus daily and consistently run out of Cursor's 500 premium requests before the month ends.

Performance Differences: 3.7 vs 4 Sonnet vs 4 Opus

Speed

Model	Average Response Time	Best For
Claude 3.7 Sonnet	1.5-2.5s	General coding (legacy)
Claude 4 Sonnet	1.2-2.0s	Daily coding, fast feedback
Claude 4 Opus	3-6s	Complex problems, deep analysis

Claude 4 Sonnet is slightly faster than 3.7, while Opus is intentionally slower due to its deeper reasoning.

Code Quality

Based on community feedback and informal testing:

Metric	3.7 Sonnet	4 Sonnet	4 Opus
Correctness (first pass)	78%	85%	92%
Idiomatic code style	Good	Very Good	Excellent
Multi-file coherence	Fair	Good	Very Good
Edge case handling	Fair	Good	Excellent
Explanation clarity	Good	Very Good	Excellent

When to Use Each Model

Claude 4 Sonnet -- your daily driver:

• Writing new features
• Refactoring existing code
• Debugging errors
• Writing tests
• Code review assistance

Claude 4 Opus -- the specialist:

• Architecture decisions
• Complex algorithm design
• Security audits
• Performance optimization
• Debugging mysterious issues

Claude 3.7 Sonnet -- if still available:

• Fallback when 4 Sonnet is unavailable
• Conserving premium requests (if 3.7 costs less)

Migration Tips: Moving from 3.7 to 4

If you have been using Claude 3.7 and are considering the switch to Claude 4, here is how to migrate smoothly.

1. Start with Sonnet, Not Opus

Do not jump straight to Opus. Claude 4 Sonnet is the logical successor to 3.7 Sonnet and will feel familiar. Opus is overkill for routine tasks and will burn through your request budget.

2. Adjust Your Prompts Slightly

Claude 4 is better at following complex instructions, which means you can be more specific:

Claude 3.7 prompt (worked well):
"Refactor this function to be cleaner"

Claude 4 prompt (even better):
"Refactor this function to use early returns, reduce nesting,
and extract the validation logic into a helper function.
Keep the public API unchanged."

3. Expect Different Output Lengths

Claude 4 tends to be more thorough in its explanations. If you prefer brevity, add to your prompt:

"Provide the code only, no explanation needed."

4. Test Your Existing Workflows

Some users reported that Composer behaves slightly differently with Claude 4:

• It may suggest more files to modify (usually correctly)
• It is more likely to ask for confirmation on destructive changes
• Multi-step tasks take fewer back-and-forth messages

Run a few test tasks on a branch before relying on Claude 4 for critical work.

5. Monitor Your Request Usage

Claude 4 may use more or fewer requests than 3.7 depending on your workflow:

• Fewer requests: Because 4 gets it right more often, you may need fewer follow-up corrections
• More requests: Because 4 gives more thorough answers, you may hit output limits and need to continue

Track your usage for the first week to understand the impact.

Known Issues and Quirks

Claude 4 Availability

Claude 4 is not always instantly available in Cursor when Anthropic announces it. There is typically a delay of a few days to weeks while Cursor integrates the new model. If you do not see Claude 4 in your model dropdown:

1. Check that your Cursor app is updated to the latest version
2. Verify your subscription is active
3. Check the Cursor forum for announcements about model rollout

Regional Restrictions

Some regions have delayed access to newer Claude models due to regulatory or contractual reasons. If Claude 4 is not available in your region, Claude 3.7 remains a strong alternative.

Output Truncation

Claude 4 Opus, in particular, can generate very long responses. Cursor has output limits, and you may see:

"The response was truncated. Continue?"

Click Continue to receive the rest. For very large tasks, consider breaking them into smaller prompts.

Summary

Claude 4 represents a meaningful upgrade for Cursor users, particularly in code correctness and multi-file reasoning. Claude 4 Sonnet should be your default for daily work, while Opus is reserved for the hardest problems.

Key takeaways:

• Claude 4 Sonnet is faster and more accurate than 3.7 for most coding tasks
• Claude 4 Opus is the highest-quality model but consumes requests rapidly
• Both require a Pro or Business subscription
• Set Claude 4 Sonnet as your default model in Settings
• Consider Claude Max ($100-200/mo) if you consistently hit Cursor's request limits
• Adjust your prompts to take advantage of 4's improved instruction following
• Test existing workflows before migrating critical projects

The model landscape changes quickly. Claude 4 is the best option for coding in Cursor as of mid-2025, but new models and pricing changes are always on the horizon. Stay updated through Cursor's changelog and the community forum.

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Last updated: June 2025