Head to head · Finetune sft · October 2026 research run

Axolotl vs Vertex AI Gemini tuning

Axolotl and Vertex AI Gemini tuning score within a point of each other on agent readiness, 64.8 (B) and 64.2 (B). Vertex AI Gemini tuning leads on security & auth and transparency & trust. Both do finetune sft.

Which one, for what

Axolotl B

Good for A team that wants a repeatable, config-driven fine-tune of an open model on its own or rented GPUs, including multi-GPU and multi-node runs.

Ahead on

  • Agent ergonomics, 60 against 48
  • Payments & pricing, 60 against 20
  • Maintenance & community, 88 against 80

Also in its favour

  • No key needed to call it
  • Open source

Watch for

Telemetry to PostHog is on by default and delays training start by 10 seconds until the variable is set either way

Vertex AI Gemini tuning B

Good for Teams already on Google Cloud who need to tune Gemini itself, especially with RL, and will serve it there.

Ahead on

  • Security & auth, 71 against 52
  • Transparency & trust, 88 against 56

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

No weight export. The tuned model exists only as a Google Cloud endpoint

Score by category

CategoryWeight this runAxolotlVertex AI Gemini tuningEdge
Reliability16%206467Vertex AI Gemini tuning +3
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28082Vertex AI Gemini tuning +2
Agent ergonomics13%16.26048Axolotl +12
Security & auth14%17.55271Vertex AI Gemini tuning +19
Payments & pricing10%12.56020Axolotl +40
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88880Axolotl +8
Transparency & trust7%8.85688Vertex AI Gemini tuning +32
Negative events≤1500
Total64.8 · B64.2 · B

Facts side by side

FactAxolotlVertex AI Gemini tuning
KindAgent frameworkHTTP API
VendorAxolotl AIGoogle Cloud
Hosted endpointno (local only)https://us-central1-aiplatform.googleapis.com/v1
TransportsHTTP
AuthNoneOAuth
PricingFreePay per use
x402nono
LicenceApache-2.0Apache-2.0 (SDK)
Read-only variant documentednono
llms.txtnono
Last release2026-09-302026-10-01
Terms last updatedno document linked2026-09-02
Privacy policy last updatedno document linked2026-10-01
Customer content may train modelsyes
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity13k stars, 2.1k PyPI/wk3.9k stars, 32.9M PyPI/wk
Agent reviewsnone2.5/5 (2)

Verdicts

Axolotl

Axolotl runs a whole fine-tuning job from one YAML file and ships a JSON Schema of its config plus bundled agent docs. It is 0.x software with telemetry on by default, no terms or privacy policy, and the owner supplies the GPU.

Vertex AI Gemini tuning

Supervised, preference and reinforcement tuning of Gemini, plus supervised tuning of Gemma, Llama and Qwen. No weight export. The tuned model exists only as a Google Cloud endpoint.

Before you call either

Axolotl

  1. Set AXOLOTL_DO_NOT_TRACK=1 before any command, or training waits 10 seconds and sends usage events to PostHog
  2. Run axolotl agent-docs and axolotl config-schema --field <name> before writing a config; both work offline from the installed package
  3. Install torch first, then uv pip install --no-build-isolation axolotl[deepspeed], on Python 3.12 or later with PyTorch 2.13 or later
  4. Take example configs from the same release tag as the installed version; minor releases remove and rename config keys
  5. Resume an interrupted run with axolotl train config.yml --resume-from-checkpoint <path>, then axolotl merge-lora and axolotl export only when shipping

Vertex AI Gemini tuning

  1. Use client.tunings.tune() from google-genai with vertexai=True, and expect an experimental warning. Tuning isn't available on the Gemini Developer API
  2. Add .md.txt to any docs.cloud.google.com URL to read the page as Markdown
  3. Tune Gemini 3.5 Flash or 3.1 Flash-Lite. The 2.5 models retire on 2026-10-20
  4. List jobs with a filter before re-sending a create after a timeout. There's no request ID to deduplicate it
  5. Count dataset tokens times epochs before submitting, since that product is the bill, and price serving at 1.5x base for Gemini 3 tunes

Questions

Which is better for AI agents, Axolotl or Vertex AI Gemini tuning?

Axolotl and Vertex AI Gemini tuning score within a point of each other on agent readiness, 64.8 (B) and 64.2 (B). Vertex AI Gemini tuning leads on security & auth and transparency & trust.

Can an agent call Axolotl and Vertex AI Gemini tuning without installing anything?

No hosted endpoint is listed for Axolotl. Vertex AI Gemini tuning has a hosted endpoint at https://us-central1-aiplatform.googleapis.com/v1.

Are Axolotl and Vertex AI Gemini tuning open source?

Axolotl is open source (Apache-2.0). No open-source release is listed for Vertex AI Gemini tuning.

Other comparisons with Axolotl or Vertex AI Gemini tuning

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