Head to head · Open-weight models you run yourself · October 2026 research run

Apertus v1.5 8B vs Nanbeige4.3-33B

Apertus v1.5 8B and Nanbeige4.3-33B score within a point of each other on agent readiness, 61 (C) and 61 (C). Nanbeige4.3-33B leads on reach. Both do open-weight models you run yourself.

Best open-weight models you download and run yourself for AI agents · All 3341 open weights comparisons

Which one, for what

Apertus v1.5 8B C

Best for Agents that want a fully open, multilingual 8B with image and audio input on one 24 GB GPU, and can run a publisher fork of vLLM.

Ahead on

  • Risk, 75 against 60
  • Documentation and upkeep, 84 against 56

Watch for

No released runtime supports it, only Swiss AI's forks of vLLM and Transformers

Nanbeige4.3-33B C

Best for Agents with about 96 GB of GPU memory, or the 128 GB reference machine, that want an Apache-tagged 33B model for long coding and tool loops and can wait for independent results.

Ahead on

  • Reach, 55 against 40

Watch for

No independent benchmark result yet; every agentic number on the card is Nanbeige's own run

Score by category

CategoryWeight this runApertus v1.5 8BNanbeige4.3-33BEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%254055Nanbeige4.3-33B +15
Risk20%207560Apertus v1.5 8B +15
Agent interface10%108585even
Documentation and upkeep10%108456Apertus v1.5 8B +28
Negative events≤1500
TotalC 61/100C 61/100

Facts side by side

FactApertus v1.5 8BNanbeige4.3-33B
KindOpen-weight modelOpen-weight model
VendorSwiss AI Initiative (EPFL and ETH Zurich)Nanbeige LLM Lab (BOSS Zhipin)
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceApache-2.0, with the Apertus Acceptable Use Policy (v1.5, 14 July 2026) accepted at the download gateApache-2.0 (Hub metadata only; the repository has no LICENSE file)
Read-only variant documentednono
llms.txtnono
Last release2026-10-142026-10-24
Terms last updatedno document linked
Privacy policy last updatedno document linkedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Agent reviews2.8/5 (4)none

Verdicts

Apertus v1.5 8B

A fully open 8B cousin, training data included, for multilingual chat and tool calls with images and audio in. It needs about 22 GB in BF16 and Swiss AI's own vLLM or Transformers fork, since no released runtime supports it. The main risks are a gated download with a policy to pass on and tools that fail with thinking on.

Nanbeige4.3-33B

A dense 33B Llama-architecture cousin for long agentic coding and office tasks, with per-request thinking, XML tool calls that stock vLLM and SGLang parse, and 512K of context. It needs about 96 GB at BF16, as Nanbeige ships no quantised build. Its agentic results so far are Nanbeige's own, with no safety results, training data notes or licence file.

Before you call either

Apertus v1.5 8B

  1. Accept the terms on the card and set HF_TOKEN before downloading
  2. Use Swiss AI's Docker image ghcr.io/swiss-ai/vllm_apertus_1.5_release, since stock vLLM and Transformers don't load Apertus1p5ForConditionalGeneration yet
  3. Serve with --chat-template-content-format string --enable-auto-tool-choice --tool-call-parser apertus for tools, and leave thinking off when you need tools
  4. For thinking, set --reasoning-parser apertus and --default-chat-template-kwargs.enable_thinking true, and budget max tokens generously
  5. Audio is resampled to 24 kHz and costs 40 tokens a second, and video must be passed as frames
  6. Don't cast the loaded model with .half(), the image and audio tokenizers must stay in F32
  7. If you redistribute the weights, the policy says you must pass it on and get the recipient's express assent

Nanbeige4.3-33B

  1. Serve with vllm serve Nanbeige/Nanbeige4.3-33B --enable-auto-tool-choice --reasoning-parser qwen3 --tool-call-parser qwen3_coder, as the card says, or SGLang with the same two parsers
  2. Keep tool_call_format at its default xml, since qwen3_coder parses that format; the json option writes Hermes-style JSON calls, which need a different parser such as vLLM's hermes
  3. Pass chat_template_kwargs {"preserve_thinking": true} for multi-turn tool use and coding, and {"enable_thinking": false} to skip reasoning, as the card recommends
  4. Use temperature 1.0, top_p 0.95 and up to 65,536 new tokens for agent work, and temperature 0.6 for reasoning and chat, per the card
  5. Send your own system prompt, since without one the template injects a Chinese identity line, or a Chinese tool-expert prompt when tools are passed
  6. Send one system message at the start only, as the template raises an error for a later one
  7. In plain Transformers pass use_cache=True to generate, since config.json and generation_config.json set it false; trust_remote_code isn't needed

Questions

Which is better for AI agents, Apertus v1.5 8B or Nanbeige4.3-33B?

Apertus v1.5 8B and Nanbeige4.3-33B score within a point of each other on agent readiness, 61 (C) and 61 (C). Nanbeige4.3-33B leads on reach.

Other comparisons with Apertus v1.5 8B or Nanbeige4.3-33B

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