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GPT-5.5 Instant
openai·openai/gpt-5.5-instant·GA·Closed·NEW
Compact GPT model for low-latency assistance and high-volume workloads
At a glance
Reference price$5.00 / $30.00 per 1M
Cache read $0.50 · ZenMux
Lowest paid$5.00 / $30.00
ZenMux Gateway
Context400,000
Output limit128,000
Capabilities
✓ Reasoning✓ Tool use✓ Structured output✓ Temperature✓ Attachments
Modalities
TextImagePDF
Knowledge cutoff2025-12-01
Released / updated2026-05-05 / 2026-05-28
Quality & performanceArtificial Analysis · Intelligence Index v4.1
Intelligence34.3
Value3
Coding—
Agentic—
Output speed—
TTFT—
Value formulaIQ 34.3 ÷ min blended $11.250 = 3
Reasoning tier → intelligence / speed (higher tier = stronger but slower)
defaultIQ 29.2 · 117 tok/s
defaultIQ 34.3
Quality is independently evaluated by Artificial Analysis. Speed/latency are model-level medians.
Available at 1 providers1 with public prices
| Provider | Tier | Input | Output | Cache read | Cache write | Context | Output limit | Status |
|---|---|---|---|---|---|---|---|---|
| ZenMux | Gateway | $5.00 | $30.00 | $0.50 | — | 400,000 | 128,000 |
Sorted by blended price (input×0.75 + output×0.25) asc. The official channel always shows regardless of rank. Whether a gateway's low price is actually usable can't be verified.
Your usage cost
1ZenMux$1,960.00
The cheapest paid channel is the only channel.
Benchmark
No upstream benchmark data for this model. For quality, see the Artificial Analysis intelligence score above.
Reasoning control
effort = loweffort = mediumeffort = high
Related models
GLM-5.2cheaper alternative$1.40 / $4.40Kimi K2.6cheaper alternative$0.95 / $4.00DeepSeek V4 Procheaper alternative$0.435 / $0.87DeepSeek V4 Flashcheaper alternative$0.14 / $0.28
Price historyone sample accumulated per data sync
Input listOutput listMin blended