Should I upgrade from GPT-5.4 to GPT-5.5?

Yes, for most use cases. GPT-5.5 is a fully retrained model that is materially better on agentic workflows (82.7% vs ~64% on Terminal-Bench 2.0), computer use, and multi-step scientific reasoning. For simple chat and classification workloads, GPT-5.4 mini remains cheaper and equally good. For agent builders, coders, and researchers, GPT-5.5 is the new default.

What's actually new in GPT-5.5?

Three big things: (1) native computer use — the model can browse, click, and iterate on web apps without a plugin; (2) agentic coding is significantly stronger, with 82.7% Terminal-Bench 2.0 and 58.6% SWE-bench Pro; (3) longer autonomous horizons — Dynamic Reasoning Time of 7+ hours on a single task in Codex. It was fully retrained, not a fine-tune of GPT-5.4.

Does GPT-5.5 cost more than GPT-5.4?

No — pricing is nearly identical. GPT-5.5 launched at roughly $1.50 input / $12 output per million tokens, matching GPT-5.4 flagship pricing. A GPT-5.5 mini tier is expected to ship in the coming weeks at GPT-5.4 mini pricing ($0.15 / $1.20). For almost every workload, upgrading is free.

Is GPT-5.4 being deprecated?

Not yet. OpenAI's Codex documentation explicitly states: 'If gpt-5.5 isn't available in your account yet, use gpt-5.4.' GPT-5.4 remains fully supported as a fallback, and OpenAI has not published a deprecation date. Expect GPT-5.4 to be available for at least 12 months, consistent with past model lifecycles.

Quick Answer

GPT-5.5 vs GPT-5.4: Should You Upgrade in April 2026?

Published: April 24, 2026

GPT-5.5 vs GPT-5.4: Should You Upgrade in April 2026?

OpenAI released GPT-5.5 on April 23, 2026. One month after GPT-5.4 became the default, OpenAI is already asking you to upgrade. Here’s the honest answer to whether you should.

Last verified: April 24, 2026

TL;DR

Upgrade if: You build agents, use Codex, do computer use, or care about multi-step reasoning. Stay on GPT-5.4 if: You run high-volume classification on GPT-5.4 mini — wait for GPT-5.5 mini. Price difference: Negligible. GPT-5.5 launched at essentially the same per-token price as GPT-5.4.

Head-to-head benchmarks

Benchmark	GPT-5.4	GPT-5.5	Delta
SWE-bench Verified	72.1%	78.2%	+6.1
SWE-bench Pro	~52%	58.6%	+6.6
Terminal-Bench 2.0	~64%	82.7%	+18.7
GDPval	~77%	84.9%	+7.9
τ²-Bench Telecom	71%	79.1%	+8.1
GPQA Diamond	84.1%	85.8%	+1.7
AIME 2026	94.7%	95.9%	+1.2
Tokens/sec	~160	~150	-6%

The pattern is clear: GPT-5.5 is a huge upgrade on agentic benchmarks (+8 to +19 points), a meaningful upgrade on coding (+6 points), and a small incremental upgrade on pure reasoning/math (+1 to +2 points).

Raw inference speed dropped slightly (~6%) because GPT-5.5 uses more “thinking” tokens per response by default.

What changed architecturally

OpenAI describes GPT-5.5 as “fully retrained.” That’s important because:

GPT-5.0 → 5.4 were incremental. They reused the base model with fine-tuning, RLHF, and safety updates. Improvements were in the 2–4 point range on most benchmarks.
GPT-5.5 is a fresh training run. Different data mix, different training objectives. That’s why the Terminal-Bench gains are 18.7 points — you can’t fine-tune your way to a delta that large.

GPT-5.5 is the first OpenAI model explicitly targeted at agentic computer use as a primary training objective, not a bolt-on capability.

Computer use: the real unlock

The biggest functional difference is native computer use. In GPT-5.4, computer use required:

Enabling the Computer Use tool in the Responses API
Extra latency (30–50% slower on UI tasks)
Occasional “I can’t see the screen” refusals

In GPT-5.5:

Computer use is a native capability, not a separate tool
Screenshots, clicks, and form fills are first-class outputs
The model self-verifies by re-checking screen state between steps
End-to-end latency on a typical “buy something on a website” task is 40% faster

If you run any browser automation, QA, or agentic workflow that touches a UI, this is the sole reason to upgrade.

Codex: upgrade is automatic

Codex CLI, the Codex IDE extension, and Codex cloud all default to gpt-5.5 as of April 23, 2026. If you use Codex, you already upgraded — nothing to do.

The OpenAI changelog also confirms:

Improved realtime handoffs (background agents receive transcript deltas)
Explicit “stay silent” option for background agents (#18597)
Host-specific remote_sandbox_config requirements (#18763)
Dynamic Reasoning Time of 7+ hours per task

The last one is the biggest deal: Codex agents can now run for an entire workday on a single complex task without losing coherence.

Pricing: essentially unchanged

Tier	GPT-5.4	GPT-5.5	Change
Input (flagship)	$1.50/1M	$1.50/1M	None
Output (flagship)	$12/1M	$12/1M	None
Mini input	$0.15/1M	Not yet shipped	—
Mini output	$1.20/1M	Not yet shipped	—

GPT-5.5 mini has not yet been released. OpenAI typically ships mini variants 2–6 weeks after the flagship, so expect it in May or early June 2026.

For now, if you run classification or cheap chatbots on GPT-5.4 mini, stay put. For everything else, the upgrade is free.

Context window and features

Feature	GPT-5.4	GPT-5.5
Context window	400K	400K
Max output	100K	100K
Native web search	✅	✅
Native image generation	✅ (DALL-E 3.5)	✅ (DALL-E 3.5)
Native voice (sub-400ms)	✅	✅
Native computer use	⚠️ via tool	✅ native
Vision	✅	✅ (upgraded)

Context window stayed at 400K — that’s still a genuine weakness vs Claude Opus 4.7 (1M) and Gemini 3.1 Pro (2M). If you work with long documents, neither GPT-5.4 nor GPT-5.5 is your best option.

The upgrade checklist

If you use GPT via API:

Change your model string from gpt-5.4 to gpt-5.5
Test your agent loop on 10 representative tasks
Watch for token usage — GPT-5.5 uses slightly more output tokens per response
Update your computer-use code — you can likely simplify by removing the explicit tool definition
Benchmark on your own data before rolling out to all traffic

If you use ChatGPT:

Nothing to do. The upgrade is automatic if you’re on Plus, Pro, Business, or Enterprise.

Verdict

For 90% of developers: upgrade to GPT-5.5 today. It is strictly better on agentic work, moderately better on coding, and identically priced. The 10% exception is high-volume mini workloads — wait for GPT-5.5 mini.

OpenAI shipped GPT-5.5 exactly one week after Anthropic’s Opus 4.7 to reclaim the agent benchmark lead. Whether that lead lasts 30 days or 90, it’s worth having on your side while it does.

Last verified: April 24, 2026. Sources: OpenAI introducing GPT-5.5, Codex changelog & models page (developers.openai.com/codex), Fortune, Axios, VentureBeat, LLM-Stats.