head-to-head

Google: Gemini 3.5 Flash vs Google: Gemini 3.1 Pro Preview Custom Tools

Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-09-23.

	Google: Gemini 3.5 Flash	Google: Gemini 3.1 Pro Preview Custom Tools
Vendor	google	google
Quality Score	100	100
Benchmark Score	53.5	-
Input Price	$1.50/M	$2.00/M
Output Price	$9.00/M	$12.00/M
Context Window	1,048,576	1,048,576
Max Output	65,536	65,536
Tool Calling	✓	✓
Structured Output	✓	✓
Reasoning Mode	✓	✓
Vision	✓	✓
Audio	✓	✓
Benchmark Scores
ai_index	53.8	-

Who wins by task?

Task	Google: Gemini 3.5 Flash	Google: Gemini 3.1 Pro Preview Custom Tools
SQL Generation	139	132
Code Review	142	132
Code Completion	119	117
Code Refactoring	144	136
Bug Fixing	146	136
Unit Test Generation	130	124
Code Documentation	134	129
Regex Writing	123	117
CI/CD Pipelines	126	120
Frontend Component Design	128	122
Data Analysis	132	124
CSV / Spreadsheet Cleanup	135	132
ETL Scripting	135	128
JSON Extraction	121	121
Bulk Data Labeling	118	117
OCR / Document Parsing	133	131
Table Extraction from PDFs	133	131
Long-Document Summarization	145	136
Short-Form Summarization	116	113
Blog Post Writing	127	120

Scores reflect capability match + benchmark data + pricing for each task. Methodology →