OpenAI
GPT-5.5
Default frontier GPT for coding, computer use, research, and knowledge work
- Context
- 1.1M
- Max output
- 128K
- Input / 1M
- $5.00
- Output / 1M
- $30.00
- Output speed
- —
Accepts
- Text input
- Image input
- PDF input
Produces
- Text output
AI model comparison
Compare recorded price, context, output limits, speed, latency, capabilities, and input/output support. Every missing value stays visible, and unsourced benchmarks are excluded.
GPT-5.5 and Step 3.7 Flash both come up when teams are choosing a model for production work, and the honest answer usually depends on your workload rather than a leaderboard. This page puts their published specifications side by side — context window, token pricing, supported inputs and outputs — so you can see where they actually differ.
OpenAI
Default frontier GPT for coding, computer use, research, and knowledge work
Accepts
Produces
StepFun
Newer StepFun flash model for faster agents, coding, and multimodal prompts
Accepts
Produces
At a glance
This is a directional summary of the values recorded in this directory—not a universal quality verdict. Test the finalists on your own prompts before committing.
Where GPT-5.5 leads in recorded data
Where Step 3.7 Flash leads in recorded data
Context capacity
Higher listed limit
GPT-5.5:1.1M
Step 3.7 Flash:256K
GPT-5.5
Maximum output
Higher listed limit
GPT-5.5:128K
Step 3.7 Flash:256K
Step 3.7 Flash
Input price
Lower recorded price
GPT-5.5:$5.00
Step 3.7 Flash:$0.18
Step 3.7 Flash
Output price
Lower recorded price
GPT-5.5:$30.00
Step 3.7 Flash:$1.11
Step 3.7 Flash
Output speed
Higher recorded throughput
GPT-5.5:—
Step 3.7 Flash:—
No complete comparison
Time to first token
Lower recorded latency
GPT-5.5:—
Step 3.7 Flash:—
No complete comparison
Intelligence Index
Higher directory index
GPT-5.5:—
Step 3.7 Flash:—
No complete comparison
Evidence
A score appears only when both records include a verified source. It is not treated as a universal ranking.
Specifications
| Specification | GPT-5.5 | Step 3.7 Flash |
|---|---|---|
| Provider | OpenAI | StepFun |
| Model family | gpt | — |
| Accepted inputs | text, image, pdf | text, image, video |
| Produced outputs | text | text |
| Context window | 1.1MRecorded lead | 256K |
| Max output | 128K | 256KRecorded lead |
| Intelligence Index | — | — |
| Input price / 1M | $5.00 | $0.18Recorded lead |
| Output price / 1M | $30.00 | $1.11Recorded lead |
| Output speed | — | — |
| Time to first token | — | — |
| Reasoning mode | Documented | Documented |
| Tool calling | Documented | Documented |
| Image input | Documented | Documented |
| Audio input | Not documented | Not documented |
| Structured output | Documented | Not documented |
| License | Proprietary | Open weights |
| Released | Apr 23, 2026 | May 29, 2026 |
Workload guidance
On the published numbers, GPT-5.5 accepts the larger context window and Step 3.7 Flash is cheaper per input token. Which matters more depends on whether your bottleneck is document size or spend — the table above has the exact figures.
Provenance
Prices and hosted performance can change. SyncDev records source references and clearly separates documented specifications from measured values; confirm commercial terms with the provider before deployment.
GPT-5.5
OpenAI · model record and recorded source
Step 3.7 Flash
StepFun · model record and recorded source
Choose any two approved model records and review them with the same evidence rules.