Data points: 125
The readout for Gemini 2.5 Flash and GPT-5.3 Codex, before the detailed comparison sheet.
Decision read
Tie
Tie currently has the stronger profile, with verified wins split 3 to 3.
Evidence depth
125 data points
Includes 30 benchmark rows, 0 audit samples, and 10 provider examples.
Selection signal
Tie
The charts below split 40 high-signal samples across speed, scores, and audit health.
Switch either side of this report to compare another model with the same LMSpeed data pipeline.
Select a different model to open a new comparison URL.
Model compare Gemini 2.5 Flash vs GPT-5.3 Codexgemini-2-5-flash-vs-gpt-5-3-codex | Model A Gemini 2.5 Flash | Model B GPT-5.3 Codex |
|---|---|---|
| Overall leader | Tie | Tie |
| Verified metric wins | 3 wins | 3 wins |
| Where it leads | Cheapest input price, Average speed, Recent tests | First-token latency, Free providers, Provider coverage |
Third-party benchmark profile synced into LMSpeed; only metrics available for both models are shown.
Compare benchmark category scores on a 0-100 scale. Select a category to inspect the gap.
Avg. score
Gemini 2.5 Flash
50
Avg. score
GPT-5.3 Codex
67.6
Selected category
Agents
GPT-5.3 Codex leads by 56.5
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
Gemini 2.5 Flash
39.0
Rank #69/96 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner82.0
Rank #8/96 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
winner230.1 tok/s
Rank #6/113 · confidence 4
GPT-5.3 Codex
89.9 tok/s
Rank #55/113 · confidence 4
Gemini 2.5 Flash
winner13.57 s
Rank #68/113 · confidence 4
GPT-5.3 Codex
87.44 s
Rank #110/113 · confidence 4
Gemini 2.5 Flash
winner13.57 s
Rank #95/113 · confidence 4
GPT-5.3 Codex
87.44 s
Rank #112/113 · confidence 4
Gemini 2.5 Flash
winner$0.300/M
Rank #41/138 · confidence 4
GPT-5.3 Codex
$1.75/M
Rank #104/138 · confidence 4
Gemini 2.5 Flash
winner$0.850/M
Rank #58/138 · confidence 4
GPT-5.3 Codex
$4.81/M
Rank #113/138 · confidence 4
Gemini 2.5 Flash
winner$2.50/M
Rank #66/138 · confidence 4
GPT-5.3 Codex
$14.00/M
Rank #113/138 · confidence 4
Gemini 2.5 Flash
42.2
Rank #44/65 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner87.7
Rank #3/65 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
45.9
Rank #53/67 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner74.0
Rank #4/67 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
1.4
Rank #33/54 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner16.9
Rank #6/54 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
79.0%
Rank #59/152 · confidence 4
GPT-5.3 Codex
winner91.5%
Rank #6/152 · confidence 4
Gemini 2.5 Flash
11.1%
Rank #67/150 · confidence 4
GPT-5.3 Codex
winner39.9%
Rank #8/150 · confidence 4
Gemini 2.5 Flash
12.1
Rank #59/69 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner53.0
Rank #5/69 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
20.4
Rank #74/83 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner83.6
Rank #7/83 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
39.4%
Rank #62/149 · confidence 4
GPT-5.3 Codex
winner53.2%
Rank #7/149 · confidence 4
Gemini 2.5 Flash
29.1
Rank #67/74 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner53.2
Rank #8/74 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
26.5
Rank #38/68 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner51.8
Rank #3/68 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
68.3
Rank #57/74 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner91.5
Rank #4/74 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
27.1
Rank #73/79 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner89.3
Rank #4/79 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
5.1
Rank #59/74 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner39.9
Rank #5/74 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
winner93.3
Rank #5/68 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
86.9
Rank #18/68 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
14.1
Rank #66/77 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner44.3
Rank #6/77 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
33.6
Rank #43/59 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner95.2
Rank #5/59 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
54.8
Rank #51/70 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner91.3
Rank #2/70 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
65.5
Rank #31/41 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner78.5
Rank #6/41 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
1158.0
Rank #41/50 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner1205.0
Rank #33/50 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
49.1
Rank #53/66 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner87.8
Rank #7/66 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
39.0
Rank #58/70 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner75.4
Rank #15/70 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
37.3
Rank #61/81 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner78.4
Rank #14/81 · confidence 1 · eval date 2026-02-05
Gemini 2.5 Flash
14.9
Rank #68/68 · confidence 1 · eval date 2025-06-17
GPT-5.3 Codex
winner86.0
Rank #30/68 · confidence 1 · eval date 2026-02-05
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | Gemini 2.5 Flash | GPT-5.3 Codex |
|---|---|---|
| No completed audits are available from shared providers yet. | ||
Speed aggregates and input/output pricing share each provider row for real API selection and migration cost checks.
| Provider | Gemini 2.5 Flash | GPT-5.3 Codex |
|---|---|---|
25 tests | Gemini 2.5 Flash speed / latency 139 tok/s / 4002ms input / output No data |
This report only uses LMSpeed data for Gemini 2.5 Flash and GPT-5.3 Codex: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Guidance | Gemini 2.5 Flash | GPT-5.3 Codex |
|---|---|---|
| When to choose each model | Gemini 2.5 Flash Gemini 2.5 Flash is stronger when you prioritize Cheapest input price, Average speed, Recent tests. | GPT-5.3 Codex GPT-5.3 Codex is stronger when you prioritize First-token latency, Free providers, Provider coverage. |
TL;DR: Tie leads across 125 verifiable data points, including pricing, speed, latency, benchmarks, and provider examples.
Continue from Gemini 2.5 Flash vs GPT-5.3 Codex into nearby model comparisons with enough verified LMSpeed data.
| Model metadata | Gemini 2.5 Flash exposes 1.0M tokens; notable signals: Text input, Image input, File input, Audio input. | GPT-5.3 Codex exposes 400K tokens; notable signals: Text input, Image input, File input, Text output. |
|---|---|---|
| Developer | OpenAI | |
| Context window | 1.0M tokens | 400K tokens |
| Max output | 65.5K tokens | 128K tokens |
| Released | Jun 2025 | Feb 2026 |
| Modalities | Input FileImageTextAudiovideo Output Text | Input TextImageFile Output Text |
| Features | Text inputImage inputFile inputAudio inputText outputTool callingStructured outputsJSON modeReasoning | Text inputImage inputFile inputText outputTool callingStructured outputs |
| Parameters | No data | No data |
| Tokenizer | Gemini | GPT |
| Knowledge cutoff | 2025-01-31 | No data |
| OpenRouter ID | google/gemini-2.5-flash | openai/gpt-5.3-codex |
| References | No data | No data |
GPT-5.3 Codex
speed / latency
N/A / N/A
input / output
No data
UoCode25 tests | Gemini 2.5 Flash speed / latency N/A / N/A input / output No data | GPT-5.3 Codex speed / latency 56 tok/s / 4621ms input / output No data |
|---|
CatClaw API10 tests | Gemini 2.5 Flash speed / latency 54 tok/s / 10365ms input / output No data | GPT-5.3 Codex speed / latency N/A / N/A input / output No data |
|---|
OpenRouter10 tests | Gemini 2.5 Flash speed / latency 141 tok/s / 2052ms input / output No data | GPT-5.3 Codex speed / latency N/A / N/A input / output No data |
|---|
QQ Code10 tests | Gemini 2.5 Flash speed / latency N/A / N/A input / output No data | GPT-5.3 Codex speed / latency 57 tok/s / 2985ms input / output No data |
|---|
Gemini 2.5 Flash gemini-2.5-flash speed / latency No data input / output $0/M / $0/M | GPT-5.3 Codex gpt-5.3-codex-openai-compact speed / latency No data input / output $75.00/M / $600.00/M |
Gemini 2.5 Flash gemini-2.5-flash-c speed / latency No data input / output $0.0027/M / $0.0027/M | GPT-5.3 Codex gpt-5.3-codex-2026-02-24 speed / latency No data input / output $10.27/M / $82.19/M |
Gemini 2.5 Flash gemini-2.5-flash speed / latency No data input / output $0.0040/M / $0.0040/M | GPT-5.3 Codex gpt-5.3-codex-openai-compact speed / latency No data input / output $3.75/M / $30.00/M |
Gemini 2.5 Flash gemini-2.5-flash-c speed / latency No data input / output $0.0050/M / $0.0050/M | GPT-5.3 Codex gpt-5.3-codex speed / latency No data input / output $0.300/M / $2.40/M |
Gemini 2.5 Flash gemini-2.5-flash speed / latency No data input / output $0.0050/M / $0.0050/M | GPT-5.3 Codex gpt-5.3-codex speed / latency No data input / output $1.75/M / $14.00/M |
Rankings are based on community-submitted tests and periodic health probes. Advisory only, not official data.
