AI model comparison
GLM 5.3 Flash vs gpt-oss-20b
Side by side comparison of GLM 5.3 Flash and gpt-oss-20b on pricing, benchmark scores, context window, and more.
GLM-5.3-Flash is a native multimodal model from Z.ai. It is suited for efficient coding and long-horizon agent tasks.
- Input / 1M
- $0.15
- Output / 1M
- $0.50
- Context
- 1.05M
gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license.
- Input / 1M
- $0.02
- Output / 1M
- $0.09
- Context
- 131K
Comparing image generators? Compare image models
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
gpt-oss-20b
6.8x cheaper for a typical chat
Higher intelligence score
Not available
Not enough benchmark data
Larger context window
GLM 5.3 Flash
1.05M vs 131K tokens
Newer release
GLM 5.3 Flash
Released August 26, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
gpt-oss-20bNot availableCoding index
gpt-oss-20b20.7Agentic index
gpt-oss-20b1.2Pricing
GLM 5.3 Flash vs gpt-oss-20b API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | gpt-oss-20b | |
|---|---|---|
| Input tokensPer 1M tokens | $0.15 | $0.02 |
| Output tokensPer 1M tokens | $0.50 | $0.09 |
| Cached input (read)Per 1M tokens | $0.03 | $0.01 |
| Cache writePer 1M tokens | Not available | Not available |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
gpt-oss-20b$0.08Coding task
30K in, 4K out
gpt-oss-20b$0.90$0.63 cachedLong document summary
150K in, 2K out
gpt-oss-20b$2.88$1.53 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | gpt-oss-20b | |
|---|---|---|
| Context window | 1.05M tokens | 131K tokens |
| Max output | 944K tokens | 33K tokens |
| Input types | Image, Text, Video | Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, High, Low | High, Medium, Low |
| Default reasoning effort | Max | Medium |
| Release date | August 26, 2026 | August 5, 2025 |
Features
Supported features
API features available for each model.
| Metric | gpt-oss-20b | |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Supported | Supported |
| Stop sequences | Supported | Supported |
| Deterministic seed | Supported | Supported |
| Verbosity control | Not supported | Not supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
- GLM 5.3 Flash vs DeepSeek V4.1 Flash 1017
- GLM 5.3 Flash vs DeepSeek V4.1 Flash
- GLM 5.3 Flash vs Hy4 preview
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- GLM 5.3 Flash vs Claude Opus 5.5
- GLM 5.3 Flash vs GLM 5.3
- GLM 5.3 Flash vs Step 5 Preview
- GLM 5.3 Flash vs MiMo-V2.6-Flash
- GLM 5.3 Flash vs DeepSeek V4 Flash 0731
- GLM 5.3 Flash vs Hy3
- GLM 5.3 Flash vs GPT-6.1 Sol
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- GLM 5.3 Flash vs DeepSeek V4 Flash 0423
- GLM 5.3 Flash vs MiniMax M3.1 Flash
- GLM 5.3 Flash vs Muse Spark 1.3 Contributor
- GLM 5.3 Flash vs Claude Sonnet 5.5
- GLM 5.3 Flash vs GPT-5.6 Luna
- GLM 5.3 Flash vs Solar Mini 4
- GLM 5.3 Flash vs Gemini 4 Argon
- GLM 5.3 Flash vs Qwen3.8 Flash
- GLM 5.3 Flash vs DeepSeek V4 Pro 0423
- GLM 5.3 Flash vs Gemini 3.1 Flash Lite
- GLM 5.3 Flash vs GPT-6 Luna Pro
- GLM 5.3 Flash vs GPT-6 Astra
- GLM 5.3 Flash vs Gemma 4 31B
- GLM 5.3 Flash vs gpt-oss-120b
- GLM 5.3 Flash vs Qwen3.7 Flash
- GLM 5.3 Flash vs Gemma 4 26B A4B
- GLM 5.3 Flash vs Gemini 2.5 Flash Lite
- GLM 5.3 Flash vs Step 3.7 Flash
- GLM 5.3 Flash vs Mistral Nemo
- GLM 5.3 Flash vs DeepSeek V3.2
- GLM 5.3 Flash vs GPT-4o-mini
- GLM 5.3 Flash vs Nemotron 3.5 Super VL
- GLM 5.3 Flash vs GLM 5.3 FlashX
- GLM 5.3 Flash vs GPT-6.1 Terra
- GLM 5.3 Flash vs Qwen3.6 35B A3B
- GLM 5.3 Flash vs GPT-5.6 Luna Pro
- GLM 5.3 Flash vs MiMo-V2.5
- GLM 5.3 Flash vs MiMo-V2.5-Pro
- GLM 5.3 Flash vs Ling 3.1 Flash
- GLM 5.3 Flash vs Muse Glimmer 30B
- GLM 5.3 Flash vs Inkling Small
- GLM 5.3 Flash vs Command A+
gpt-oss-20bView full model details- gpt-oss-20b vs DeepSeek V4.1 Flash 1017
- gpt-oss-20b vs DeepSeek V4.1 Flash
- gpt-oss-20b vs GPT-6 Luna
- gpt-oss-20b vs MiMo-V2.6-Flash
- gpt-oss-20b vs DeepSeek V4 Flash 0731
- gpt-oss-20b vs DeepSeek V4 Flash 0423
- gpt-oss-20b vs Muse Spark 1.3 Contributor
- gpt-oss-20b vs Solar Mini 4
- gpt-oss-20b vs Qwen3.7 Flash
- gpt-oss-20b vs Mistral Nemo
Our take
gpt-oss-20b is 6.8x cheaper for a typical chat. GLM 5.3 Flash has the larger context window (1.05M vs 131K tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is GLM 5.3 Flash or gpt-oss-20b cheaper?
gpt-oss-20b is cheaper for a typical chat (2K input tokens and 500 output tokens). gpt-oss-20b costs $0.02 per 1M input tokens and $0.09 per 1M output tokens, while GLM 5.3 Flash costs $0.15 per 1M input tokens and $0.50 per 1M output tokens.
Which has a bigger context window, GLM 5.3 Flash or gpt-oss-20b?
GLM 5.3 Flash supports up to 1.05M tokens of context, compared with 131K for gpt-oss-20b.
Can I use GLM 5.3 Flash and gpt-oss-20b at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see GLM 5.3 Flash and gpt-oss-20b answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to GLM 5.3 Flash and gpt-oss-20b at the same time. Compare the answers side by side and keep the best one.