What happened when Claude 4 retired on June 15?

API calls to claude-4-opus and claude-sonnet-4 model IDs now return HTTP 410 Gone errors. Your API key still works — you just need to change the model name in your code to a supported replacement.

What's the fastest migration from Claude 4?

Change claude-4-opus to claude-opus-4-8 (same provider, same API key, 67% cheaper at $5/$25 per 1M tokens). Change claude-sonnet-4 to claude-sonnet-4-6 (same price, 5x context window). One line change, 30 seconds.

Can I keep using my Claude API key after June 15?

Yes. Your Anthropic API key works with all current models including Claude Opus 4.8 and Claude Sonnet 4.6. Only the deprecated model IDs stop working.

What's the cheapest alternative to Claude 4?

DeepSeek V4 Flash at $0.14/$0.28 per 1M tokens — 99% cheaper than Claude 4 Opus. For similar quality, DeepSeek V4 Pro at $0.435/$0.87 is 97% cheaper. The direct Anthropic replacement Claude Opus 4.8 is 67% cheaper at $5/$25.

⚠️ Claude 4 shut down June 15, 2026 — migrate now

Claude 4 Is Now Offline.
Your API Calls Are Failing.

Claude 4 Opus and Sonnet 4 were retired on June 15, 2026. If your API calls are failing, here's exactly what to do — in 30 seconds.

Calculate My Savings ↓

⚠️ What Breaks on June 15

claude-4-opus

$15 / $75 per 1M tokens · 200K context

RETURNS ERROR

→ claude-opus-4-8 ($5/$25)

claude-sonnet-4

$3 / $15 per 1M tokens · 200K context

RETURNS ERROR

→ claude-sonnet-4-6 ($3/$15)

✅ These Keep Working

claude-opus-4-8 $5/$25 · 1M context

claude-sonnet-4-6 $3/$15 · 1M context

claude-haiku-4-5 $0.80/$4 · 200K context

Your API key still works — only the model name changes.

How Much Will You Save?

Enter your monthly usage. See exact savings in 2 seconds.

Input Tokens / Month (millions)

Output Tokens / Month (millions)

Claude 4 Opus (retiring) $300/mo

Claude Opus 4.8 (Anthropic) $100/mo

DeepSeek V4 Pro (cheapest similar) $6.09/mo

DeepSeek V4 Flash (cheapest overall) $2.96/mo

$193.91/mo

You save by switching from Claude 4 Opus to DeepSeek V4 Pro

Open full deprecation calculator with all 88 models →

Migrate in 30 Seconds

Find & Replace the Model Name

One line change. Your API key, SDK, and endpoint stay the same.

// Before (fails after June 15)
model: "claude-4-opus"

// After (works now, 67% cheaper)
model: "claude-opus-4-8"

Test Your Integration

Send a test request. Claude Opus 4.8 uses the same API format — no code changes needed beyond the model name.

Deploy Before June 15

That's it. You're migrated. Your costs just dropped 67-97%.

Need more help? Full migration command center →

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Common Questions

What exactly happened on June 15?

API calls to claude-4-opus and claude-sonnet-4 now return HTTP 410 Gone errors. Your API key, SDK, and account all still work — you just need to use the new model names.

Do I need a new API key?

No. If staying with Anthropic, your existing key works with Claude Opus 4.8 and Sonnet 4.6. Only the model name string changes. If switching to DeepSeek, Mistral, or others, you'll need a key from that provider.

What's the fastest migration path?

Change claude-4-opus to claude-opus-4-8. Same provider, same API key, same SDK. 67% cheaper. 30 seconds.

What if I want to switch providers?

DeepSeek V4 Pro is 97% cheaper than Claude 4 Opus with similar quality. Mistral Large is 93% cheaper. GPT-5 is comparable at $1.25/$5. All use standard REST APIs — migration takes about 15 minutes.