Expert Guide

Best AI Test Generation Tools in 2026: Prices and Free Tiers Compared

Seven tools that write tests with AI, compared on what they cost, which free tier can run a real suite, and where each one stops.

Louis CorneloupFounder, Dupple · 28,000+ Devshot subscribers · Updated Oct 2026

Product links may be affiliate links. How we rate 7 tools compared

TL;DR

Short answer: Claude Code is the agent whose vendor page says it writes code and runs tests in your repo, with Pro as its entry plan. GitHub Copilot is the cheapest paid AI assistant here at $10 a month, with a /tests command for the code you select. Keploy builds API tests from real traffic and has a free forever plan. Java and Python teams with a budget should price Diffblue, which starts at $1,500, while EvoSuite costs nothing but covers only Java.

Key facts7 tools compared: Claude Code, Cursor, GitHub Copilot, Keploy, Diffblue Testing Agent…

Updated: October 17, 2026
Top pick: Claude Code (best for: Developers who want one agent to write code, run the tests and fix what breaks in their repo)
Top pick price as of October 17, 2026: Claude Code: Pro $20/mo ($17/mo billed annually), Max from $100/mo; the Free plan excludes it

7 tools compared: Claude Code, Cursor, GitHub Copilot, Keploy, Diffblue Testing Agent, Katalon, EvoSuite
Cursor (best for: Teams that want an editor agent to build a feature and test it end to end before review): Hobby free; Pro $20/mo; Teams $40/user/mo; Enterprise custom
GitHub Copilot (best for: Developers in VS Code, Visual Studio, JetBrains or Xcode who want unit tests from one command): Free $0; Pro $10/mo; Pro+ $39/mo; Business price not shown on the plans page
Keploy (best for: Backend teams that want API and integration tests built from real recorded traffic): Free forever; Pro $19/user/mo plus usage; Enterprise custom

A generated test is cheap to produce and expensive to keep. The tools below write unit, API or UI tests, but they bill in four different units: seats, usage credits, test runs and net new lines of coverage. A plain price list misleads for that reason, so each entry shows the entry price, the free allowance and what the vendor page leaves out. Methodology: we checked each vendor's own pricing and product page on 10 October 2026, kept only the figures those pages show, and left out tools whose vendor sites do not state a clear price.

Top Picks

Based on features, real-world fit, and value for money.

#1 Top pick

Claude Code

The vendor page says Claude Code plans, writes code, runs tests and opens pull requests from your terminal, alongside your IDE.

Pricing

Pro $20/mo ($17/mo billed annually), Max from $100/mo; the Free plan excludes it

Best for

Developers who want one agent to write code, run the tests and fix what breaks in their repo

Visit Claude Code Details

Cursor

An AI code editor whose agents, per the homepage, build, test and demo features end to end for you to review.

Pricing

Hobby free; Pro $20/mo; Teams $40/user/mo; Enterprise custom

Best for

Teams that want an editor agent to build a feature and test it end to end before review

Visit Cursor Details

GitHub Copilot

Type /tests in Copilot Chat to generate unit tests for the selected code, per GitHub's cheat sheet, in four editor families.

Pricing

Free $0; Pro $10/mo; Pro+ $39/mo; Business price not shown on the plans page

Best for

Developers in VS Code, Visual Studio, JetBrains or Xcode who want unit tests from one command

Visit GitHub Copilot Details

Best AI Test Generation Tools in 2026: Prices and Free Tiers Compared: 7 tools compared, updated Oct 2026
Tool	Pricing	Best for
Claude Code	Pro $20/mo ($17/mo billed annually), Max from $100/mo; the Free plan excludes it	Developers who want one agent to write code, run the tests and fix what breaks in their repo
Cursor	Hobby free; Pro $20/mo; Teams $40/user/mo; Enterprise custom	Teams that want an editor agent to build a feature and test it end to end before review
GitHub Copilot	Free $0; Pro $10/mo; Pro+ $39/mo; Business price not shown on the plans page	Developers in VS Code, Visual Studio, JetBrains or Xcode who want unit tests from one command
Keploy	Free forever; Pro $19/user/mo plus usage; Enterprise custom	Backend teams that want API and integration tests built from real recorded traffic
Diffblue Testing Agent	Starting at $1,500 for 5,000 net new lines of coverage, $0.30 per line	Java and Python teams with large codebases that want unit tests added and verified automatically
Katalon	Free edition: 40 static test suites; Professional $1,000/seat/yr billed annually (first 3 seats)	QA teams that want low-code test automation with AI generation and self-healing, not unit tests
EvoSuite	Free and open source under LGPL-3.0; no vendor price	Java teams that want free, automatic JUnit suites and will review every generated assertion

Pricing read from each vendor's own pricing page, checked Oct 2026. 2 of 7 publish prices for some plans and quote the rest.

Lowest monthly figure each vendor publishes, checked Oct 2026. A tilde marks a figure the vendor states approximately. Per-seat and usage charges can sit on top of it. 3 of 7 do not publish a comparable monthly price and are left out rather than estimated.

Top Pick

Claude Code

The vendor page says Claude Code plans, writes code, runs tests and opens pull requests from your terminal, alongside your IDE.

Pricing: Pro $20/mo ($17/mo billed annually), Max from $100/mo; the Free plan excludes it

Best for: Developers who want one agent to write code, run the tests and fix what breaks in their repo

Pros

The vendor page says it plans, writes code, runs tests and opens pull requests in one task
Included in Pro, so a developer who already pays for Pro can try it without a new seat
The vendor page says it keeps going when something breaks, which suits a failing test loop

Cons

The page says it runs tests and writes code, but it does not say in so many words that it writes test files
The Free plan has no Claude Code, so the first paid step is Pro

Cursor

An AI code editor whose agents, per the homepage, build, test and demo features end to end for you to review.

Pricing: Hobby free; Pro $20/mo; Teams $40/user/mo; Enterprise custom

Best for: Teams that want an editor agent to build a feature and test it end to end before review

Pros

Hobby tier is free with no credit card, and includes limited agent requests
Pro is a flat monthly price for an individual, with extended agent limits
Teams adds centralized team billing at a per-user price

Cons

Usage beyond the plan allowance is billed on demand, so the monthly bill can rise
The homepage says agents test features but does not say they write test files

GitHub Copilot

Type /tests in Copilot Chat to generate unit tests for the selected code, per GitHub's cheat sheet, in four editor families.

Pricing: Free $0; Pro $10/mo; Pro+ $39/mo; Business price not shown on the plans page

Best for: Developers in VS Code, Visual Studio, JetBrains or Xcode who want unit tests from one command

Pros

The cheapest paid AI assistant on this list, with Pro below the agents' entry price
The Free plan includes 2,000 completions and 50 chat requests a month
The scope is the selection you highlight, so you decide which function gets tests

Cons

GitHub's cheat sheet lists /tests for the editors but not for the GitHub website, so it is an editor feature
The plans page shows no Business price, so the team cost is not listed there

Keploy

Records real requests, then generates API and integration tests from them. The core record-and-replay platform is open source under Apache 2.0.

Pricing: Free forever; Pro $19/user/mo plus usage; Enterprise custom

Best for: Backend teams that want API and integration tests built from real recorded traffic

Pros

Generates API tests from traffic, specifications and application context, per its FAQ
The core local record-and-replay platform is open source under Apache 2.0
The free forever plan includes 30 test-suite generations, 100 test runs and 5 AI credits a month

Cons

Recording from Kubernetes, staging and production is listed as an enterprise capability
Usage beyond the included amounts is billed per test generation at $0.16 and per test run at $0.22

Diffblue Testing Agent

Autonomous AI unit testing that bills only for net new lines of coverage that compile, pass and add to the codebase.

Pricing: Starting at $1,500 for 5,000 net new lines of coverage, $0.30 per line

Best for: Java and Python teams with large codebases that want unit tests added and verified automatically

Pros

You pay only for net new lines of coverage that compile and pass, a metric any coverage tool can check
Supports Java 8, 11, 17, 21 and 25, plus Python 3.9 and later
The page prices coverage delivered rather than seats or API calls, so adding reviewers does not raise the bill

Cons

Java and Python only, so JavaScript, TypeScript and Go teams are out of scope
The pricing page does not state a billing period, so the yearly cost is unclear

Katalon

A test automation platform whose Professional plan adds AI agents for test automation, per its pricing page.

Pricing: Free edition: 40 static test suites; Professional $1,000/seat/yr billed annually (first 3 seats)

Best for: QA teams that want low-code test automation with AI generation and self-healing, not unit tests

Pros

The Professional plan includes AI agents for low-code authoring, failure analysis and self-healing
The free edition covers local authoring and execution at no cost
The Enterprise plan is quote-only and includes the same AI features

Cons

The $1,000 per seat price covers only the first three seats and runs until October 31, against a $2,199 original price
The free edition has no AI script generation, no parallel or cloud runs and no CI execution

EvoSuite

A free Java tool that automatically generates JUnit test suites for Java classes. It is a search-based generator, not a chat assistant.

Pricing: Free and open source under LGPL-3.0; no vendor price

Best for: Java teams that want free, automatic JUnit suites and will review every generated assertion

Pros

Open source under LGPL-3.0, with the jar and plugins available from evosuite.org
Generates JUnit suites for Java classes without a prompt
The source is on GitHub, so you can read what the generator does before you rely on it

Cons

Java only, so it gives nothing for Python, TypeScript or Go
Generated assertions record current behaviour, so a bug in the code can end up in the test

What it is

An AI test generation tool reads your code, a set of recorded API calls or a browser flow, and writes test files that run in your own suite. Unit tests check one function or class. API and integration tests replay real requests against a service. UI and end-to-end tests drive a browser through a flow. Most entries are strongest in one layer, so match the tool to the layer where your bugs appear.

Why it matters

Writing a test takes minutes, reviewing one takes longer, and a generated test that records today's output can lock a bug in. Devshot data: Toolradar, the software directory we run, tracks 11,051 tools across 343 categories, and its AI testing category page was checked in October 2026. The number that decides the budget is the one your team hits first: seats for a small team, test runs for a CI pipeline, or lines of coverage for a large Java codebase.

Key features to look for

Test layerEssential

Diffblue writes unit tests for Java and Python, EvoSuite for Java, Keploy builds API and integration tests from traffic, and Katalon sells low-code test automation with self-healing. Pick the layer where your bugs actually appear.

Billing unitEssential

Diffblue bills net new lines of coverage, Keploy bills test generations and test runs, Katalon bills per seat per year, and the assistants bill usage against a plan allowance. Compare on the unit your team hits first.

Free allowance

Copilot Free includes 2,000 completions and 50 chat requests a month. Keploy's free plan covers 30 test-suite generations and 100 test runs. Katalon's free edition caps you at 40 static suites with no AI generation.

Language limits

Diffblue covers Java 8 to 25 and Python 3.9 and later, and EvoSuite covers Java only. The assistant pages we read name no language limit, so test one real file before you commit.

Review gate

A generated test often asserts what the code does today, so it can pass a bug. Read each assertion before the file merges.

Pricing

On the vendor pages we read on 10 October 2026, the cheapest paid AI assistant is GitHub Copilot Pro at $10 a month. The two agents share an entry price, with Claude Pro also offered at $17 a month when billed annually. Keploy's paid plan is $19 per user a month plus usage, and Diffblue starts at $1,500 for 5,000 lines of net new coverage on its pricing page. Katalon's Professional plan is $1,000 per seat a year only for the first three seats until October 31, against a $2,199 original price. EvoSuite has no vendor price because it is open source.

Plan	Price	Best for
Claude Free	$0	No Claude Code, so no agent test runs
Claude Pro	$20/mo ($17/mo billed annually)	Claude Code included; annual billing is $200 up front
Claude Max	From $100/mo	Claude Code included; billed monthly only
Cursor Hobby	Free	Limited agent requests, no credit card needed
Cursor Pro	$20/mo	Individual plan with extended agent limits
Cursor Teams	$40/user/mo	Centralized team billing
GitHub Copilot Free	$0	2,000 completions and 50 chat requests a month
GitHub Copilot Pro	$10/mo	Unlimited inline suggestions; usage counted in AI Credits
GitHub Copilot Pro+	$39/mo	Listed above Pro on the plans page, with no annual option shown
Keploy Free Forever	Free	30 test-suite generations, 100 test runs, 5 AI credits a month
Keploy Pro	$19/user/mo plus usage	Monthly or yearly billing, with an included usage credit
Keploy Enterprise	Custom	Recording from Kubernetes, staging and production
Diffblue Testing Agent	Starting at $1,500	5,000 net new lines of coverage, with $0.30 per line as the effective cost
Katalon Free	Free	Up to 40 static test suites, local authoring and execution only
Katalon Professional	$1,000/seat/yr (first 3 seats, until October 31)	AI agents for test automation; the page shows $2,199 per seat as the original price
EvoSuite	Free	Open source under LGPL-3.0, Java only

Mistakes to avoid

×Buying on the entry price alone. Diffblue's starting price covers 5,000 lines, and Keploy's usage is billed on top of its per-user price.

×Trusting a green run. A generated test that asserts today's output passes even when today's output is wrong.

×Generating tests for code nobody owns. A test that nobody maintains becomes the CI failure everyone learns to ignore.

×Choosing a tool before checking its language list. Diffblue covers Java and Python, and EvoSuite covers only Java.

Expert tips

→Run the trial on one real file rather than a demo repo, and count how many generated tests you would keep.

→Read every assertion before you merge, and reject any test that only checks that the function returns something.

→Keep the tests in the repo next to the code they cover, so a change and its test land in the same pull request.

→Count your test generations on one service before you scale a trial, since Keploy's free plan includes a fixed allowance of them.

The bottom line

Pick by the layer your bugs live in. For an agent that writes code and runs the tests in your own repo, Claude Code or Cursor are the strongest fit. For the lowest paid entry, GitHub Copilot covers unit tests from a single command. For API tests built from real traffic, Keploy with its free forever plan is the one to try. For Java or Python at scale, Diffblue bills by coverage and EvoSuite is the free Java option. Full profiles on Toolradar: Keploy, Cursor and GitHub Copilot.

Cite this: Devshot, Best AI Test Generation Tools in 2026: Prices and Free Tiers Compared, checked October 2026.

Frequently asked questions

What is the best AI test generation tool in 2026?

For an agent that writes code and runs the tests in your own repo, Claude Code or Cursor. For API tests built from real traffic, Keploy. For Java or Python unit tests at scale, Diffblue. There is no single winner because each one bills and covers a different layer.

Is there a free AI test generation tool?

Yes, with limits. Keploy's free forever plan allows 30 test-suite generations and 100 test runs a month, GitHub Copilot Free allows 50 chat requests, and EvoSuite is open source for Java. Katalon's free edition has no AI generation.

Which tools generate unit tests for Python?

Diffblue supports Python 3.9 and later alongside Java. EvoSuite is Java only. The assistant pages we read name no language limit, but test one real file before you rely on a tool for Python.

How much does AI test generation cost per developer?

The lowest paid entry is GitHub Copilot Pro. Keploy Pro is $19 per user a month plus usage, and Katalon's Professional plan is sold per seat. Keploy, Cursor and Katalon list their enterprise plans as custom or quote-only.

Can I trust a generated test?

Only after you read it. A generated test often records what the code does today, so a bug can pass. Review each assertion, then run the full suite on the branch before you merge.

Sources

Prices and plan details come from each vendor's own pricing page, re-checked by the Toolradar pricing tracker.