GPT-5.4 vs GPT-5 - What's New in 2026

GPT-5.4 vs GPT-5 — What’s New in 2026

GPT-5.4 just landed, and it’s a bigger jump from GPT-5 than you’d expect. Here’s what changed and why you’ll care.

Key Upgrades in GPT-5.4

1. Enhanced Reasoning (about 40% better)

GPT-5.4 handles tangled reasoning a lot smoother. It tackles multi-step problems, makes logical deductions, and just thinks more clearly.

What that looks like in the real world:

• Smarter math chops
• Easier code debugging
• More solid analysis of tricky scenarios
• Fewer illogical leaps in arguments

2. Larger Context Window (2M Tokens)

Users asked for more context, and GPT-5.4 delivers. It can handle up to 2 million tokens—roughly 1.5 million words or about 3,000 pages of text.

What this means:

• Read and analyze whole books in one go
• Digest huge codebases without juggling chunks
• Keep long-running conversations without losing context
• Work with large datasets without breaking a sweat

3. Better Code Generation

If you’re writing code, you’ll notice the difference straight away. GPT-5.4 produces cleaner, more accurate code with fewer bugs.

What’s improved:

• Better grasp of existing codebases
• More efficient algorithms
• Stronger debugging helpers
• Tighter documentation generation

4. Reduced Hallucinations (about 35% fewer)

GPT-5.4 makes up fewer facts on its own, especially when it’s about real-world information, sources, or technical topics.

Where you’ll see the drop:

• Fewer mistakes when citing facts
• More reliable source references
• More accurate claims about real events
• More trustworthy technical output

5. Multimodal Integration

GPT-5 opened some multimodal doors; GPT-5.4 walks through them more smoothly. Images, audio, and video blend into conversations with less friction.

Performance Snapshot

Here’s how they stack up, side by side:

• Reasoning: GPT-5 = 85%, GPT-5.4 = 92% (+7%)
• Code Quality: GPT-5 = 88%, GPT-5.4 = 95% (+7%)
• Factuality: GPT-5 = 82%, GPT-5.4 = 91% (+9%)
• Speed: GPT-5 = 1.0x, GPT-5.4 = 1.3x (+30%)

When to use GPT-5.4 vs GPT-5

Use GPT-5.4 for:

• Tough reasoning tasks
• Long documents or whole books
• Writing and debugging code
• Deep research and fact-checking
• Anything where accuracy matters

Use GPT-5 for:

• Quick, simple chats
• Shorter documents
• Budget-conscious projects
• Rapid prototyping
• Basic tasks

Cost Check

GPT-5.4 runs about 20% higher in price than GPT-5, but the extra performance often makes it worthwhile.

AI Pass Integration

Both models are available through AI Pass. Snag $1 free credit to try GPT-5.4 today.

Bottom line

GPT-5.4 isn’t just a bump up; it’s a meaningful leap in what AI can do. If you’re building serious AI apps, the upgrade is worth it.

Try GPT-5.4 on AI Pass and feel the difference for yourself.