Choose DeepSeek: DeepSeek V4.1 Flash if…
No advantage on the data we track — pick it for provider preference or output quality on your own prompts.
DeepSeek: DeepSeek V4.1 Flash vs Z.ai: GLM 5.3 Flash
Z.ai: GLM 5.3 Flash comes out ahead on the data we track: 1 advantage and none for DeepSeek: DeepSeek V4.1 Flash.
Key numbers
| Spec | DeepSeek: DeepSeek V4.1 Flash | Z.ai: GLM 5.3 Flash |
|---|---|---|
| Provider | DeepSeek | Z Ai |
| Input price (per 1M tokens) | $0.30 | $0.15 |
| Output price (per 1M tokens) | $1.20 | $0.50 |
| Blended price (3:1 input/output) | $0.52 | $0.24 |
| Cheaper than … of all models we track | 52% | 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 | 944K tokens (~707,800 words) | 944K tokens (~707,800 words) |
| Input types | text, image | text, image, video |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2026-09-10 | 2026-08-26 |
What it costs for real workloads
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) | DeepSeek: DeepSeek V4.1 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) | $46.50 | $21.25 | Z.ai: GLM 5.3 Flash saves $25.25 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $48.00 | $23.00 | Z.ai: GLM 5.3 Flash saves $25.00 |
| 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) | $50.40 | $24.00 | Z.ai: GLM 5.3 Flash saves $26.40 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $31.20 | $15.00 | Z.ai: GLM 5.3 Flash saves $16.20 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $16.20 | $8.00 | Z.ai: GLM 5.3 Flash saves $8.20 |
Capabilities side by side
| Capability | DeepSeek: DeepSeek V4.1 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 | — | — | take speech or audio directly |
| File / PDF input | — | — | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | — | answer from live web results |
| Seed (reproducible sampling) | ✓ Yes | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | ✓ Yes | ✓ Yes | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- DeepSeek: DeepSeek V4.1 Flash: input price raised 99% ($0.0030 → $0.30/1M), output price cut 50% ($2.40 → $1.20/1M) on 2026-10-06 (16 price changes since 2026-09-11).
- 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).
| Date | Model | Input / 1M | Output / 1M |
|---|---|---|---|
| 2026-10-07 | Z.ai: GLM 5.3 Flash | $0.15 | $0.50 |
| 2026-10-06 | DeepSeek: DeepSeek V4.1 Flash | $0.30 | $1.20 |
| 2026-10-06 | Z.ai: GLM 5.3 Flash | $0.03 | $0.50 |
| 2026-10-04 | DeepSeek: DeepSeek V4.1 Flash | $0.0030 | $2.40 |
| 2026-10-03 | DeepSeek: DeepSeek V4.1 Flash | $0.30 | $1.20 |
| 2026-10-02 | DeepSeek: DeepSeek V4.1 Flash | $0.02 | $0.75 |
| 2026-10-01 | DeepSeek: DeepSeek V4.1 Flash | $0.02 | $0.40 |
| 2026-09-29 | DeepSeek: DeepSeek V4.1 Flash | $0.30 | $1.20 |
Which should you choose?
Choose Z.ai: GLM 5.3 Flash if…
- cost matters at scale — it is 55% cheaper on a typical 3:1 input/output mix ($21.25 vs $46.50 a month for 50,000 support chats)
Frequently asked questions
Is DeepSeek: DeepSeek V4.1 Flash better than Z.ai: GLM 5.3 Flash?
Z.ai: GLM 5.3 Flash comes out ahead on the data we track: 1 advantage and none for DeepSeek: DeepSeek V4.1 Flash.
Which is cheaper, DeepSeek: DeepSeek V4.1 Flash or Z.ai: GLM 5.3 Flash?
Z.ai: GLM 5.3 Flash is cheaper: $0.24 vs $0.52 per 1M tokens at a typical 3:1 input/output mix, 55% less. For 50,000 support conversations a month that is $21.25 against $46.50.
How much do DeepSeek: DeepSeek V4.1 Flash and Z.ai: GLM 5.3 Flash cost per million tokens?
DeepSeek: DeepSeek V4.1 Flash costs $0.30 per 1M input tokens and $1.20 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.
Which has the bigger context window, DeepSeek: DeepSeek V4.1 Flash or Z.ai: GLM 5.3 Flash?
Both take 1.0M tokens per request — roughly 1,573 pages of text.
Do DeepSeek: DeepSeek V4.1 Flash and Z.ai: GLM 5.3 Flash support function calling and JSON output?
Tool calling — DeepSeek: DeepSeek V4.1 Flash: yes, Z.ai: GLM 5.3 Flash: yes. JSON-schema structured output — DeepSeek: DeepSeek V4.1 Flash: yes, Z.ai: GLM 5.3 Flash: yes.
Can DeepSeek: DeepSeek V4.1 Flash or Z.ai: GLM 5.3 Flash read images?
Yes, both accept image input.
Is DeepSeek: DeepSeek V4.1 Flash or Z.ai: GLM 5.3 Flash free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of DeepSeek: DeepSeek V4.1 Flash and Z.ai: GLM 5.3 Flash?
DeepSeek: DeepSeek V4.1 Flash can write up to 944K tokens (about 707,800 words) per response; Z.ai: GLM 5.3 Flash up to 944K (about 707,800 words).
When were DeepSeek: DeepSeek V4.1 Flash and Z.ai: GLM 5.3 Flash released?
DeepSeek: DeepSeek V4.1 Flash was listed on 2026-09-10; Z.ai: GLM 5.3 Flash on 2026-08-26.
Has the price of DeepSeek: DeepSeek V4.1 Flash or Z.ai: GLM 5.3 Flash changed?
DeepSeek: DeepSeek V4.1 Flash: input price raised 99% ($0.0030 → $0.30/1M), output price cut 50% ($2.40 → $1.20/1M) on 2026-10-06 (16 price changes since 2026-09-11). 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).
About the two models
DeepSeek: DeepSeek V4.1 Flash
DeepSeek V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder (CED) architecture. It activates 8B parameters on input and 16B on...
Full DeepSeek: DeepSeek V4.1 Flash specs →Z.ai: GLM 5.3 Flash
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 →