ModelPickr

Compare / GPT

GPT · canonical pair

GPT-5.5 vs GPT-6 Astra

Alphabetical by model id, so this URL is the one to index. GPT-5.5 is openai/gpt-5.5. GPT-6 Astra is openai/gpt-6-astra. Both are among the models the most providers list, inside the GPT group.

A

GPT-5.5

$75.00

per month at the reference workload

  • Reasoning
  • Tool use
  • Structured output
  • Vision
  • Long context

vs

B

GPT-6 Astra

$135

per month at the reference workload

  • Reasoning
  • Tool use
  • Structured output
  • Vision
  • Long context
100 requests a day, 2,000 input tokens and 500 output tokens, no cache hits. A light chat workload so the rate cards are comparable.
SpecGPT-5.5GPT-6 Astra
Monthly, reference workload$75.00$135
Input / 1M$5.00$10.00
Output / 1M$30.00$50.00
Cache read / 1M$0.50$1.00
Cache write / 1M—$12.50
Context1,050,0001,050,000
Max output128,000128,000
ReasoningYesYes
Tool callsYesYes
VisionYesYes
Open weightsNoNo
Providers4532
Released2026-04-232026-09-04

Same workload, your numbers

Prices are USD per 1M tokens. A month is 30 days. Cache hits use the cache-read rate when the model has one; otherwise the cache field is ignored.

Estimated monthly cost

GPT-5.5

$75.00

GPT-6 Astra costs $60.00 more per month than GPT-5.5 at these inputs.

monthly = requests/day × 30 × (input tokens × (1 − cache hit) × input price + input tokens × cache hit × cache-read price + output tokens × output price) ÷ 1,000,000