Automated regression unit test generation at scale

The Diffblue Testing Agent orchestrates your AI coding tools to create comprehensive, high quality test coverage with developer intervention so you can modernize legacy code with confidence
The Problem

AI coding agents can’t deliver comprehensive coverage

You need 80%+ coverage. Claude and Copilot demand constant developer babysitting and still won’t get you close.

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Low coverage despite endless prompting

Our benchmark research shows that hours of work and continuous prompting still results in low test coverage.

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Constant context switching = AI toil

Checking in on your unpredictable agent every few minutes is the new developer productivity destroyer. Context switching kills.

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Verification is the new bottleneck

Making sure AI-generated code doesn’t break requires high regression unit test coverage. Guaranteeing the tests are right requires Diffblue.

AI coding agents weren’t built for automatically generating tests at project-level scale. The Diffblue Testing Agent was.

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HOW WE'RE DIFFERENT

Your AI coding agents generate individual tests. The Diffblue Testing Agent automatically orchestrates the entire process until the job is done: coverage analysis, build system fixes, test plan creation, parallelized test generation, output verification, project clean-up, and PR preparation.

They generate. We guarantee.

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  • 01
    From AI code to production code
    AI coding agents produce code quickly, including tests. But "produced" isn't "production-ready." Without verification, orchestration, and rollback, AI-generated tests create more work, not less.
  • 02
    From AI output to production-ready tests
    Diffblue Agents uses your existing, enterprise-approved AI coding platform as the engine — then wraps it in a decade of test engineering expertise: scoping, sequencing, verification, and quality guarantees that turn raw AI output into tests you'd actually merge.
  • Tick GreenWorks with your enterprise-approved AI stack.
  • Tick GreenNo new LLM vendor to evaluate.
AI coding agents
+ Senior Developer
AI coding agents
+ Diffblue Testing Agent
Scope
Manual prompting
Entire codebase, autonomous
Developer effort
Constant monitoring & rework
Zero — point, run, walk away
Error handling
Garbage left behind, manual clean-up
Automated fixing and clean-up
Scale
Incremental progress
Hundreds of classes, parallelised
Expertise
Ad-hoc prompting
10 years of test engineering workflows
* Internal benchmark across 8 enterprise-grade Java repositories totalling 31,069 coverable lines. See benchmarks below.
BENCHMARK RESULTS

Don't take our word for it. See the data.

Diffblue Testing Agent vs. Sr.Developer + Claude CodeInternal benchmark across 8 enterprise-grade Java repositories totalling 31,069 coverable lines. All repositories started from 0% test coverage.

Java · Customer-provided project · 20k LoC (9k coverable lines)
Diffblue Testing Agent
+ Claude Code
Claude Code
+ Sr. Developer
Avg. line coverage
80.7%
32.3%
Avg. mutation coverage
61.3%
24.2%
Avg. test strength
81.8%
73.9%
Human intervention required
Setup only
510 minutes (8.5 hrs)
Across 8 anonymized Java repos · 31,069 coverable lines · All starting at 0% coverage
HOW IT WORKS

Point it at the repo.
Walk away.

Diffblue Agents CLI processes your entire codebase autonomously — including legacy Java 8 and 11 codebases that generic AI tools struggle with.

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Platform compatibility

Works with your enterprise-approved AI stack

Supported
CoPilot Logo

Diffblue Agents for GitHub Copilot

Enterprise test generation that makes your Copilot investment pay off

Supported
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Diffblue Agents for Claude Code

Autonomous test generation with the reliability Claude alone can't deliver

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Java 8, 11, 17, 21, 25

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Python

Coming Soon

Gemini CLI— Coming soon

Coming Soon

Codex— Coming soon

Pricing

Outcome-based pricing that scales with your value

Every line you’re charged for represents a unit test that compiles, passes, and improves your coverage. You’re only charged for tests that actually work.

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Charged per verified line of coverage added

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Tests designed to achieve high mutation testing scores

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Scales naturally — more repos 
= more coverage = more value

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Every Diffblue-generated test is verified to compile and pass before delivery

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No maintenance renewal problem — pay once for coverage delivered

ENTERPRISE TRUST

Built for organizations that can't afford to get testing wrong

Banks need months of security review. Defense contractors require air-gapped solutions. Diffblue has been earning that trust for a decade.

Lines tested in production

2745
5
6109
9
M +

Years of dev time saved

3691
1
,
9640
0
9810
0
9740
0

Production outages saved

4311
1
2170
0
9370
0
0490
0
s

In production since

5312
2
6170
0
0261
1
8106
6

Banks need months of security review. Defense contractors require air-gapped solutions. Healthcare companies need audit trails. Diffblue has been earning that trust for a decade.

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Oxford University spin-out — formal methods heritage

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Fortune 500 customers in financial services, insurance, technology

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Diffblue CLI runs locally — your code stays in your environment

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On-premises solutions available for regulated environments

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Need a fully on-prem, no-LLM solution?

Diffblue Cover provides deterministic, offline Java unit test generation for environments that require air-gapped deployment with zero external dependencies.

Autonomous unit test generation for enterprise codebases

Run the Diffblue Testing Agent on your codebase. See the coverage
results. Deploy with the AI coding platform you already use.