Describe and refine
Start with a plain-English prompt, then answer follow-up questions that sharpen behavior, tone, and boundaries.
Pipeline BuilderCUSTOM FINE-TUNING, MADE LEGIBLE
Turn one prompt into a custom fine-tuned character or assistant.
Describe what you want in plain English. TunerBench turns it into a full spec, generates a dataset, filters it with a judge, trains the model, and lets you test and download everything.
Dataset generation report
We generate candidate training examples, then keep only the ones that fit the spec.
Prompt input
Detailed
Generated pairs
Analyzed
Accepted
Refined
Built for people who want a custom model without learning fine-tuning first
Character agents
Custom assistants
Voice and style tuning
Prototype workflows
PLATFORM
Everything you need to go from idea to tuned model.
Generate and filter data
TunerBench creates Q&A pairs from the spec and shows which examples the judge accepts or rejects.
Meta promptingTrain, test, and export
Kick off training, try the model in a hosted chat, and download the resulting outputs when you are ready.
Release VaultWORKFLOW
A guided flow from idea to custom model.
01
Write what you want
Describe your target character or assistant in plain English.
02
Answer follow-up questions
Refine the model’s tone, constraints, and boundaries.
03
Review the generated spec
TunerBench formulates a structured specification based on your answers.
04
Generate and filter the dataset
Automatically produce Q&A pairs and use a judge to keep only the best.
05
Train, test, and download
Kick off training, test the result in a hosted chat, and download the artifacts.
How it works
Constitutional filtering + rejection sampling = higher signal data.
One model generates many candidate conversations. A second model acts as a judge and filters each output against rules you define. We keep the best examples and reject the rest.
01
Generate candidates
Produce diverse conversations that match your character's spec.
02
Judge with rules
Apply constitutional feedback with explicit, auditable guardrails.
03
Reject + retain
Keep only the most consistent, high-quality examples.
04
Train and download
Train the model, try it in the playground, and download the weights.
Generator
14x conversations
Diverse prompts per character.
Judge
Rule checks
Constitutional alignment rules.
Filter
Reject failures
Drop off-voice responses.
Dataset
Clean JSONL
Structured, consistent output.
WHY TUNERBENCH
Most fine-tuning workflows are too manual or too opaque.
TunerBench is built to make custom fine-tuning easier to use and easier to understand. You can see the spec, watch the data get generated, track what gets rejected, try the trained model, and keep the outputs.
- No fine-tuning background required
- Visible data generation and filtering
- Hosted testing before download
FAQ
Answers for teams moving to custom models.
Do I need fine-tuning experience?
No. TunerBench handles the underlying complexity. You just need to know what you want the model to sound like.
What can I build with it today?
You can build custom character models and specialized assistants that follow strict rules and tone guidelines.
Can I review the dataset?
Yes. The generated Q&A pairs are fully legible and filterable before training begins.
Can I try the model before downloading?
Yes. We host a temporary playground so you can chat with your tuned model and verify its behavior.
Can I download the dataset too?
Yes. Both the final weights and the structured JSONL dataset are yours to keep.
Is this still in beta?
Yes. We’re working closely with early users to refine the workflow before general availability.
BETA
Try TunerBench on a real use case.
The product is live and usable. We are looking for early users who want to build custom characters and assistants and give feedback on the workflow.
We will email you when early access opens.