Was ZAI GLM-5.3 Flash the stealth model Ox Alpha?

Yes, the stealth model Ox Alpha was revealed to be ZAI's new model, GLM-5.3 Flash.

Where is the GLM 5.3 Flash (batch) documentation?

The GLM 5.3 Flash (batch) documentation on OpenRouter includes the Open-Weight vs Closed-Weight Models: What's the Difference? blog post. The quickstart covers API keys and your first request, and the API reference lists every parameter.

How much does GLM 5.3 Flash (batch) cost?

GLM 5.3 Flash (batch) costs $0.05/M input tokens and $0.18/M output tokens, with separate rates for Cache Read at $0.01/M tokens.

What is the context length of GLM 5.3 Flash (batch)?

GLM 5.3 Flash (batch) has a 1,048,576 token context window. It supports up to 131,072 completion tokens.

Does GLM 5.3 Flash (batch) support tool calling and structured outputs?

Yes. GLM 5.3 Flash (batch) accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.

What inputs and outputs does GLM 5.3 Flash (batch) support?

GLM 5.3 Flash (batch) accepts text, images, and video as input and returns text.

Which providers serve GLM 5.3 Flash (batch)?

GLM 5.3 Flash (batch) is served by 3 providers on OpenRouter: Sail Research, Together, and DeepInfra. Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.

When was GLM 5.3 Flash (batch) released?

GLM 5.3 Flash (batch) was released on August 26, 2026.

Z.ai: GLM 5.3 Flash (batch)

z-ai/glm-5.3-flash:batch

Model weights

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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 reducing compute overhead.

Modalities

In / out price

$0.05 / $0.18per 1M

Context

1.0M

Released

Aug 26, 2026

Providers

Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick: Balanced (price + speed), Nitro (fastest), or Floor (cheapest).


$0.05	$0.18	$0.01	--	--	--
$0.075	$0.25	$0.015	--	--	--
$0.12	$0.40	$0.024	--	--	--

Input $0.05Output $0.18
-- tok/s-- uptime
Input $0.075Output $0.25
-- tok/s-- uptime
Input $0.12Output $0.40
-- tok/s-- uptime

Pricing

The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.

Weighted average

Input

$0/M tokens

Output

$0/M tokens

GLM 5.3 Flash (batch) — Price history

Price history

No effective price data for this selection

$0.00	$0.00	7.8%	99.6%
$0.00	$0.00	6.7%	0.1%
$0.00	$0.00	0.0%	0.2%

Effective in $0.00Effective out $0.00
Token share
99.6%
Effective in $0.00Effective out $0.00
Token share
0.1%
Effective in $0.00Effective out $0.00
Token share
0.2%

Uptime

Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.

Not enough uptime data to display yet.

When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.

Benchmarks

Scores on standardized evaluations and this model’s own outputs on shared benchmark prompts. Higher percentages are better — and each rank shows where this model lands among the models evaluated on that source.

Benchmark score summary for Z.ai: GLM 5.3 Flash (batch) (Artificial Analysis, Design Arena and Vals AI)
Source	Benchmark	Score
Artificial Analysis	GLM-5.3-Flash Intelligence Index	27.8
Artificial Analysis	GLM-5.3-Flash Coding Index	71.5
Artificial Analysis	GLM-5.3-Flash Agentic Index	50.9
Artificial Analysis	GLM-5.3-Flash GPQA Diamond	91.2%
Artificial Analysis	GLM-5.3-Flash HLE	39.9%
Artificial Analysis	GLM-5.3-Flash AA-LCR	80.0%
Artificial Analysis	GLM-5.3-Flash τ-Bench Banking	47.2%
Artificial Analysis	GLM-5.3-Flash GDPval-AA	57.4%
Artificial Analysis	GLM-5.3-Flash CritPt	15.4%
Artificial Analysis	GLM-5.3-Flash SciCode	51.6%
Artificial Analysis	GLM-5.3-Flash Terminal-Bench 4.0	32.8%
Artificial Analysis	GLM-5.3-Flash Terminal-Bench 2.1	84.3%
Artificial Analysis	GLM-5.3-Flash AA-Omniscience Accuracy	28.2%
Artificial Analysis	GLM-5.3-Flash AA-Omniscience Non-Hallucination Rate	61.7%
Design Arena	GLM-5.3-Flash Models Arena 3D Elo	1293
Design Arena	GLM-5.3-Flash Models Arena Asciiart Elo	1269
Design Arena	GLM-5.3-Flash Models Arena Code Categories Elo	1267
Design Arena	GLM-5.3-Flash Models Arena Data Visualization Elo	1258
Design Arena	GLM-5.3-Flash Models Arena Game Development Elo	1266
Design Arena	GLM-5.3-Flash Models Arena SVG Elo	1271
Design Arena	GLM-5.3-Flash Models Arena UI Component Elo	1296
Design Arena	GLM-5.3-Flash Models Arena Website Elo	1257
Vals AI	GLM 5.3 Flash Access to Justice Benchmark	71.1%
Vals AI	GLM 5.3 Flash Code Migration v1.1	51.6%
Vals AI	GLM 5.3 Flash CyberBench v1.1	67.9%
Vals AI	GLM 5.3 Flash CyberOffense	18.3%
Vals AI	GLM 5.3 Flash EMB v1.1	66.3%
Vals AI	GLM 5.3 Flash Finance Agent v2.1	60.6%
Vals AI	GLM 5.3 Flash Vals Finance Index	55.8%
Vals AI	GLM 5.3 Flash GPQA Diamond	86.4%
Vals AI	GLM 5.3 Flash HLAB-Vals-1.1	10.4%
Vals AI	GLM 5.3 Flash IOI	52.5%
Vals AI	GLM 5.3 Flash LiveCodeBench	80.5%
Vals AI	GLM 5.3 Flash LegalBench	83.9%
Vals AI	GLM 5.3 Flash Vals Legal Index	71.1%
Vals AI	GLM 5.3 Flash Legal Research Bench	45.2%
Vals AI	GLM 5.3 Flash MedScribe	88.9%
Vals AI	GLM 5.3 Flash MMLU Pro	86.1%
Vals AI	GLM 5.3 Flash MMMU Pro	86.0%
Vals AI	GLM 5.3 Flash ProgramBench	0.0%
Vals AI	GLM 5.3 Flash ProofBench v1.1	21.0%
Vals AI	GLM 5.3 Flash SAGE	89.3%
Vals AI	GLM 5.3 Flash SkillsBench	40.2%
Vals AI	GLM 5.3 Flash SRE Bench	0.8%
Vals AI	GLM 5.3 Flash SWE-bench	92.0%
Vals AI	GLM 5.3 Flash Tax Agent Bench	31.6%
Vals AI	GLM 5.3 Flash TaxEval v2	75.6%
Vals AI	GLM 5.3 Flash Terminal-Bench 4.0	37.4%
Vals AI	GLM 5.3 Flash Terminal-Bench-Science	2.9%
Vals AI	GLM 5.3 Flash Vals Index	50.9%
Vals AI	GLM 5.3 Flash Vibe Code Bench 1-100	16.0%
Vals AI	GLM 5.3 Flash Vibe Code Bench v1.1	30.8%

Z.ai: GLM Flash versions

Not currently available through EU in-region routing. In-region routing docs

More models from Z.ai

GLM 5.3 FlashX Legal

GLM-5.3-FlashX-Legal (GLM-Legal) is Z.ai's legal-domain variant of GLM-5.3-FlashX, a native multimodal model that accepts text, image, and video input and produces text. It adds legal-domain mid-training and post-training with reinforcement learning in task environments modeled on real legal workflows, targeting document understanding, legal reasoning, and multi-step task execution such as legal research, contract review, cross-document consistency checks, and drafting or revising legal documents.

It keeps the GLM-5.3-FlashX 1M-token context window, mandatory thinking mode, function calling, structured output, and streaming, and is designed to run in agent setups connected to legal data and document-editing tools (MCP services).

Text1.0M context$0.37 / $1.25

GLM 5.3 Prime

GLM-5.3-Prime is the high-speed variant of Z.ai's GLM-5.3, inheriting its full capabilities while delivering 1.5–2× the output throughput through inference acceleration. It supports text input and output with a 1M-token context window and up to 128K output tokens, and targets coding and agentic workloads, including long-horizon multi-turn agent orchestration, real-time conversation, and streaming code generation.

Reasoning is always on and cannot be disabled. Reasoning efforts low, high, and max are supported; max is the default.

Text1M context$2.80 / $8.80

GLM 5.3 FlashX

GLM-5.3-FlashX is the high-speed variant of Z.ai's GLM-5.3-Flash, a native multimodal model delivering inference speeds of up to 200 tokens/s. Built on the same hybrid sparse and linear attention architecture (320B total parameters, 18B active), it is suited for efficient coding, visual understanding, and long-horizon agent tasks with a 1M-token context window.

Text1.0M context$0.37 / $1.25

GLM Flash Latest

This model always redirects to the latest model in the GLM Flash family.

Text1.0M context

GLM 5.3 Flash

Text1.0M context$0.0399 / $0.0784

GLM 5.3 Flash (batch)

Text1.0M context$0.05 / $0.18

GLM Latest

This model always redirects to the latest GLM model from Z.ai.

Text1.0M context

GLM 5.3

GLM-5.3 is a large-scale reasoning model from Z.ai, built for complex software engineering and long-horizon agent tasks. It supports text input and output with a 1M-token context window, and improves on GLM-5.2 in coding and in the balance between performance and token efficiency.

Reasoning is always on and cannot be disabled. Reasoning efforts low, high, and max are supported; max is the default.

Text1.0M context$0.0699 / $1.40

GLM 5.3 (batch)

Reasoning is always on and cannot be disabled. Reasoning efforts low, high, and max are supported; max is the default.

Text1.0M context$0.45 / $2

GLM 5.2

GLM 5.2 is a large-scale reasoning model from Z.ai. It supports text input and output with a 1M-token context window, and is suited for long-horizon agent workflows, project-level software engineering, and complex multi-step automation.

Reasoning efforts high and xhigh are supported; xhigh maps to max reasoning. It is particularly strong at coding and tool use across long-running tasks, able to maintain engineering context and follow standards consistently through a full development workflow, from requirements to multi-platform deployment, in a single task.

Text1.0M context$0.0066 / $7.983

GLM 5.2 (batch)

Text1.0M context$0.347 / $1.068

GLM 5.1

GLM-5.1 delivers a major leap in coding capability, with particularly significant gains in handling long-horizon tasks. Unlike previous models built around minute-level interactions, GLM-5.1 can work independently and continuously on a single task for more than 8 hours, autonomously planning, executing, and improving itself throughout the process, ultimately delivering complete, engineering-grade results.

Text205K context$0.8988 / $2.825

GLM 5V Turbo

GLM-5V-Turbo is Z.ai’s first native multimodal agent foundation model, built for vision-based coding and agent-driven tasks. It natively handles image, video, and text inputs, excels at long-horizon planning, complex coding, and task execution, and works seamlessly with agents to complete the full loop of “perceive → plan → execute“.

Text203K context$1.20 / $4

GLM 5 Turbo

GLM-5 Turbo is a new model from Z.ai designed for fast inference and strong performance in agent-driven environments such as OpenClaw scenarios. It is deeply optimized for real-world agent workflows involving long execution chains, with improved complex instruction decomposition, tool use, scheduled and persistent execution, and overall stability across extended tasks.

Text203K context$1.20 / $4

GLM 5

GLM-5 is Z.ai’s flagship open-source foundation model engineered for complex systems design and long-horizon agent workflows. Built for expert developers, it delivers production-grade performance on large-scale programming tasks, rivaling leading closed-source models. With advanced agentic planning, deep backend reasoning, and iterative self-correction, GLM-5 moves beyond code generation to full-system construction and autonomous execution.

Text205K context$0.60 / $1.92

GLM 4.7 Flash

As a 30B-class SOTA model, GLM-4.7-Flash offers a new option that balances performance and efficiency. It is further optimized for agentic coding use cases, strengthening coding capabilities, long-horizon task planning, and tool collaboration, and has achieved leading performance among open-source models of the same size on several current public benchmark leaderboards.

Text200K context$0.0605 / $0.40

GLM 4.7

GLM-4.7 is Z.ai’s latest flagship model, featuring upgrades in two key areas: enhanced programming capabilities and more stable multi-step reasoning/execution. It demonstrates significant improvements in executing complex agent tasks while delivering more natural conversational experiences and superior front-end aesthetics.

Text205K context$0.40 / $1.75

GLM 4.6V

GLM-4.6V is a large multimodal model designed for high-fidelity visual understanding and long-context reasoning across images, documents, and mixed media. It supports up to 128K tokens, processes complex page layouts and charts directly as visual inputs, and integrates native multimodal function calling to connect perception with downstream tool execution. The model also enables interleaved image-text generation and UI reconstruction workflows, including screenshot-to-HTML synthesis and iterative visual editing.

Text131K context$0.30 / $0.90

GLM 4.6

Compared with GLM-4.5, this generation brings several key improvements:

Longer context window: The context window has been expanded from 128K to 200K tokens, enabling the model to handle more complex agentic tasks. Superior coding performance: The model achieves higher scores on code benchmarks and demonstrates better real-world performance in applications such as Claude Code、Cline、Roo Code and Kilo Code, including improvements in generating visually polished front-end pages. Advanced reasoning: GLM-4.6 shows a clear improvement in reasoning performance and supports tool use during inference, leading to stronger overall capability. More capable agents: GLM-4.6 exhibits stronger performance in tool using and search-based agents, and integrates more effectively within agent frameworks. Refined writing: Better aligns with human preferences in style and readability, and performs more naturally in role-playing scenarios.

Text205K context$0.43 / $1.75

GLM 4.5V

GLM-4.5V is a vision-language foundation model for multimodal agent applications. Built on a Mixture-of-Experts (MoE) architecture with 106B parameters and 12B activated parameters, it achieves state-of-the-art results in video understanding, image Q&A, OCR, and document parsing, with strong gains in front-end web coding, grounding, and spatial reasoning. It offers a hybrid inference mode: a "thinking mode" for deep reasoning and a "non-thinking mode" for fast responses. Reasoning behavior can be toggled via the reasoning enabled boolean. Learn more in our docs

Text66K context$0.60 / $1.80

Z.ai: GLM 5.3 Flash (batch)

Providers

Pricing

Weighted average

GLM 5.3 Flash (batch) — Price history

Performance

Uptime

Benchmarks

Apps

Activity

API

Documentation

Frequently asked questions

Explore more models

More models from Z.ai

More models from Z.ai

Z.ai: GLM 5.3 Flash (batch)

Providers

Pricing

Weighted average

GLM 5.3 Flash (batch) — Price history

Performance

Uptime

Benchmarks

Apps

Activity

API

Documentation

Frequently asked questions

Was ZAI GLM-5.3 Flash the stealth model Ox Alpha?

What is GLM 5.3 Flash (batch)?

Where is the GLM 5.3 Flash (batch) documentation?

How much does GLM 5.3 Flash (batch) cost?

What is the context length of GLM 5.3 Flash (batch)?

Does GLM 5.3 Flash (batch) support tool calling and structured outputs?

What inputs and outputs does GLM 5.3 Flash (batch) support?

Which providers serve GLM 5.3 Flash (batch)?

When was GLM 5.3 Flash (batch) released?

Explore more models

More models from Z.ai

More models from Z.ai