Neither wins outright: Google: Gemini 2.5 Flash is the pick when you need audio input, Z.ai: GLM 5.3 Flash when cost matters at scale.
| Spec | Google: Gemini 2.5 Flash | Z.ai: GLM 5.3 Flash |
|---|---|---|
| Provider | Z Ai | |
| Input price (per 1M tokens) | $0.30 | $0.15 |
| Output price (per 1M tokens) | $2.50 | $0.50 |
| Blended price (3:1 input/output) | $0.85 | $0.24 |
| Cheaper than … of all models we track | 43% | 67% |
| Context window | 1.0M tokens (~1,573 pages) | 1.0M tokens (~1,573 pages) |
| Larger context than … of all models | 81% | 81% |
| Max output per response | 66K tokens (~49,200 words) | 944K tokens (~707,800 words) |
| Input types | file, image, text, audio, video | text, image, video |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-06-17 | 2026-08-26 |
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | Google: Gemini 2.5 Flash | Z.ai: GLM 5.3 Flash | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $72.50 | $21.25 | Z.ai: GLM 5.3 Flash saves $51.25 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $61.00 | $23.00 | Z.ai: GLM 5.3 Flash saves $38.00 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $66.00 | $24.00 | Z.ai: GLM 5.3 Flash saves $42.00 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $39.00 | $15.00 | Z.ai: GLM 5.3 Flash saves $24.00 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $17.50 | $8.00 | Z.ai: GLM 5.3 Flash saves $9.50 |
| Capability | Google: Gemini 2.5 Flash | Z.ai: GLM 5.3 Flash | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | ✓ Yes | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | ✓ Yes | — | take speech or audio directly |
| File / PDF input | ✓ Yes | — | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | ✓ Yes | — | answer from live web results |
| Seed (reproducible sampling) | ✓ Yes | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | — | ✓ Yes | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
| Date | Model | Input / 1M | Output / 1M |
|---|---|---|---|
| 2026-10-07 | Z.ai: GLM 5.3 Flash | $0.15 | $0.50 |
| 2026-10-06 | Z.ai: GLM 5.3 Flash | $0.03 | $0.50 |
| 2026-09-28 | Z.ai: GLM 5.3 Flash | $0.15 | $0.50 |
| 2026-09-26 | Z.ai: GLM 5.3 Flash | $0.04 | $0.50 |
| 2026-09-25 | Z.ai: GLM 5.3 Flash | $0.04 | $0.60 |
| 2026-09-22 | Z.ai: GLM 5.3 Flash | $0.15 | $0.50 |
| 2026-09-17 | Z.ai: GLM 5.3 Flash | $0.09 | $0.30 |
| 2026-09-16 | Z.ai: GLM 5.3 Flash | $0.10 | $0.33 |
Neither wins outright: Google: Gemini 2.5 Flash is the pick when you need audio input, Z.ai: GLM 5.3 Flash when cost matters at scale. In short: Google: Gemini 2.5 Flash when you need audio input, you need file / PDF input, you need built-in web search; Z.ai: GLM 5.3 Flash when cost matters at scale, you need log-probabilities, you generate long outputs in one go, you want the newer model.
Z.ai: GLM 5.3 Flash is cheaper: $0.24 vs $0.85 per 1M tokens at a typical 3:1 input/output mix, 72% less. For 50,000 support conversations a month that is $21.25 against $72.50.
Google: Gemini 2.5 Flash costs $0.30 per 1M input tokens and $2.50 per 1M output tokens; Z.ai: GLM 5.3 Flash costs $0.15 input and $0.50 output. Output tokens are billed separately, so long answers shift the gap.
Both take 1.0M tokens per request — roughly 1,573 pages of text.
Tool calling — Google: Gemini 2.5 Flash: yes, Z.ai: GLM 5.3 Flash: yes. JSON-schema structured output — Google: Gemini 2.5 Flash: yes, Z.ai: GLM 5.3 Flash: yes.
Yes, both accept image input.
No free variant is listed for either; both are pay-per-token.
Google: Gemini 2.5 Flash can write up to 66K tokens (about 49,200 words) per response; Z.ai: GLM 5.3 Flash up to 944K (about 707,800 words).
Google: Gemini 2.5 Flash was listed on 2025-06-17; Z.ai: GLM 5.3 Flash on 2026-08-26.
Google: Gemini 2.5 Flash: price unchanged since we started tracking it on 2026-03-10. Z.ai: GLM 5.3 Flash: input price raised 81% ($0.03 → $0.15/1M) on 2026-10-07 (10 price changes since 2026-08-27).
Gemini 2.5 Flash is Google's state-of-the-art workhorse model, specifically designed for advanced reasoning, coding, mathematics, and scientific tasks. It includes built-in "thinking" capabilities, enabling it to provide responses with greater...
Full Google: Gemini 2.5 Flash specs →GLM-5.3-Flash is a native multimodal model from Z.ai. It is suited for efficient coding and long-horizon agent tasks. Its hybrid sparse and linear attention architecture maintains accurate long-context behavior while...
Full Z.ai: GLM 5.3 Flash specs →