🚨 Last Chance — Claude 4 Migration

Claude 4 Last Chance — 4 Days Until API Shutdown

Claude 4 Opus and Sonnet 4 stop working June 15. No extensions, no grace period. Here's everything you need to migrate in under 30 minutes.

Published Jun 11, 2026 · 8 min read · Updated daily until deadline

4 DAYS REMAINING
Claude 4 Opus and Claude 4 Sonnet API calls will fail after June 15, 2026. No extensions. No grace period. No exceptions.

This is it. Four days before Claude 4 Opus and Claude 4 Sonnet shut down permanently. If you haven't started your migration yet, you're cutting it close — but you can still finish in time. This guide gives you the fastest path off Claude 4 with the least risk.

~96
hours until Claude 4 API calls start failing

The 30-Minute Migration Checklist

Here's exactly what to do, in order. Most developers finish this in 15-30 minutes:

1

Find Every Claude 4 Reference

Run this in your project root:

grep -r "claude-4-opus\|claude-4-sonnet" --include="*.js" --include="*.ts" --include="*.py" --include="*.json" .

This finds every file that references the deprecated model IDs. Don't forget config files, environment variables, and documentation.

2

Update Model IDs

The API format is identical — you only change the model name:

// Before (deprecated — will fail June 15)
model: "claude-4-opus"

// After (official successor)
model: "claude-opus-4-8"

No other code changes needed. Same API, same SDK, same parameters.

3

Test and Deploy

Make a few test calls to verify the new model works with your prompts. Then deploy. That's it — you're migrated.

Cost Comparison: Claude 4 vs Alternatives

Here's what you're paying now vs what you could pay after migration (per 1M tokens):

Claude 4 Opus (current)
$15 / $75
Input / Output — RETIRING
Claude Opus 4.8 (successor)
$5 / $25
67% cheaper · Same API format
Claude 4 Sonnet (current)
$3 / $15
Input / Output — RETIRING
Claude Sonnet 4.6 (successor)
$3 / $15
Same price · 5x context window

Budget Alternatives (if you want to save even more)

DeepSeek V4 Pro
$0.44 / $0.87
97% cheaper than Claude 4 Opus
Llama 4 Maverick
$0.27 / $0.85
98% cheaper · Open source
⚡ Pro

Calculate Your Exact Savings

Enter your monthly token usage and see exactly how much you'll save by migrating off Claude 4.

Try Calculator →

What If You're Using Claude 4 Through a Third Party?

If you access Claude 4 via OpenRouter, Amazon Bedrock, or another provider, you still need to update your model ID. Some providers may have already removed Claude 4 from their available models list. Check your provider's dashboard for the latest status.

LangChain and LlamaIndex Users

Update your model string in the chat instantiation:

# LangChain
chat = ChatAnthropic(model="claude-opus-4-8")  # was "claude-4-opus"

# LlamaIndex
llm = Anthropic(model="claude-opus-4-8")  # was "claude-4-opus"

Both libraries use the same underlying SDK — only the model ID changes.

Why Migrate to Claude Opus 4.8?

Claude Opus 4.8 is the official successor to Claude 4 Opus. It offers:

Don't Wait Until June 15

Use the APIpulse cost calculator to see exactly how much you'll save, then migrate today. It takes 30 minutes — your app will be cheaper and more reliable.

Calculate Your Savings →

Frequently Asked Questions

Can I get an extension on the Claude 4 deadline?

No. Anthropic has confirmed there is no grace period, no extension, and no degraded mode. The shutdown is hard: June 15, 2026.

What if I miss the deadline?

Your API calls will fail immediately with a 404 error. You'll need to update your model ID and redeploy. There's no way to keep using Claude 4 after June 15.

Will my prompts work the same on Claude Opus 4.8?

Yes. Claude Opus 4.8 uses the same API format and responds to the same prompts. You may see slightly different outputs (it's a newer model), but your existing prompts will work without modification.

What if I have fine-tuned Claude 4 models?

Fine-tuned models will also stop working. You'll need to re-fine-tune on Claude Opus 4.8 or Claude Sonnet 4.6. Contact Anthropic support for guidance on transferring fine-tuned weights.

Is it worth switching to a cheaper provider like DeepSeek?

It depends on your quality requirements. DeepSeek V4 Pro is 97% cheaper and handles most tasks well, but Claude Opus 4.8 may be better for complex reasoning. Use the APIpulse comparison tool to test both against your use case.

Pro

Track All Model Deprecations Automatically

APIpulse Pro monitors 39 models across 10 providers and alerts you before any price change or deprecation.

Get Pro — $29 →

Related Reading