Fix: Claude Code Slow Responses (30+ Seconds)

Claude Code responses should be fast. If you’re waiting 30+ seconds regularly, something’s wrong.

Common Causes

1. Context bloat

The most common cause. Your session has accumulated too much context.

Symptoms:

• Responses get slower over time
• Started fast, now slow
• Been in session for 1+ hours

Fix:

/compact

Or start a fresh session.

2. Large file reads

Reading huge files slows everything down.

Symptoms:

• Slow after reading specific files
• Working with large codebases

Fix: Read selectively:

# Instead of
Read the entire database.ts file

# Do this
Read lines 100-200 of database.ts

3. Network issues

Your connection to Anthropic’s servers is slow.

Symptoms:

• Slow from session start
• Other internet services also slow
• Timeouts

Fix:

# Test API directly
time curl -s https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "content-type: application/json" \
  -d '{"model":"claude-sonnet-4-20250514","max_tokens":10,"messages":[{"role":"user","content":"hi"}]}'

If slow, check your network or try a VPN.

4. Rate limiting

You’re hitting API limits.

Symptoms:

• Intermittent slowness
• Sometimes fast, sometimes very slow
• 429 errors appear

Fix:

• Wait and retry
• Upgrade your plan
• Reduce request frequency

5. Wrong model

Opus is slower than Sonnet, which is slower than Haiku.

Symptoms:

• Consistently slow on all tasks
• Using Opus for simple questions

Fix:

/model sonnet

Or for simple tasks:

/model haiku

Diagnosis Steps

Step 1: Check context size

Look at the token counter:

[tokens: 150k/200k]  ← High usage

If above 100k, run /compact.

Step 2: Check session duration

How long have you been in this session?

• Under 30 min: Probably not context bloat
• Over 1 hour: Likely context bloat

Step 3: Test with fresh session

# Exit current session
Ctrl+C

# Start fresh
claude

If fresh session is fast, the old session was bloated.

Step 4: Test API directly

time claude --headless "Say hello"

If this is slow, it’s network or rate limiting.

Step 5: Check model

What model are you using?

If Opus, switch to Sonnet for faster responses.

Quick Fixes

Immediate relief

/compact

Reduces context by summarizing history.

Change model

/model haiku

Fastest responses for simple tasks.

Start fresh

claude --session "new-task"

Clean context, fast responses.

Prevention

1. Compact regularly

Every 30-45 minutes in long sessions:

/compact

2. Use appropriate model

Task	Model
Quick questions	Haiku
Most coding	Sonnet
Complex architecture	Opus

3. Read files selectively

# Good
Read the handleLogin function in auth.ts

# Avoid
Read the entire 2000-line auth.ts

4. Start fresh for new tasks

Don’t continue old sessions for unrelated work.

5. Monitor token usage

Watch the status bar. Compact before hitting 70%.

Measuring Response Time

In-session timing

Claude shows response time after each message.

Headless benchmarking

# Time a simple task
time claude --headless "What is 2+2?"

# Expected: Under 5 seconds

Compare models

time claude --headless --model haiku "Simple task"
time claude --headless --model sonnet "Simple task"
time claude --headless --model opus "Simple task"

When Slowness Is Expected

Some operations are legitimately slow:

Operation	Expected Time
Simple question	2-5 seconds
Code generation	5-15 seconds
Multi-file refactor	15-30 seconds
Complex analysis	30-60 seconds

If you’re within these ranges, it’s normal.

Escalation

If nothing helps:

1. Check Anthropic status page
2. Try again later
3. Contact support with:
   • Session ID
   • Approximate time
   • What you were doing

Quick Reference

Symptom	Likely Cause	Fix
Slow over time	Context bloat	/compact
Slow from start	Network/model	Check connection, use Haiku
Intermittently slow	Rate limiting	Wait, upgrade plan
Slow after file read	Large files	Read selectively
Always slow	Wrong model	/model sonnet