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Developer Tools · head to head

ESLint vs Heap

ESLint logo

ESLint

Developer Tools

Find and fix problems in JavaScript code

From
Free
Free plan
Yes
Full reviewWebsite
Heap logo

Heap

Technology

Product analytics for the modern product team

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: ESLint slow performance on large codebases compared to newer tools like Oxlint and Biome; Heap no built-in A/B testing or feature flags; requires integration with separate tools for experimentation
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which ESLint and Heap actually diverge.

Attributes where ESLint and Heap differ
AttributeESLintHeap
PlatformsBrowser-based JavaScript, Node.js, Any JavaScript environmentWeb, iOS, Android
CategoryDeveloper ToolsTechnology
Founded20192013

Identical on both: starting price (Free), pricing model (Unknown), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in ESLint

Nothing recorded that Heap does not also cover.

Only in Heap

  • Autocapture
  • Retroactive analytics
  • Session replay
  • Funnel analysis
  • User segmentation
  • Path analysis
  • Data science
  • Virtual events

What people use each for

The jobs each tool is most often brought in to do.

ESLint

  • Statically analysing JavaScript and JSX to find problems before runtimenot Heap
  • Automatically fixing issues with syntax-aware rewritesnot Heap
  • Enforcing a consistent code style across a teamnot Heap
  • Running as a CI step to block non-conforming codenot Heap
  • Writing custom rules for project-specific conventionsnot Heap

Heap

  • User behavior analysisnot ESLint
  • Conversion optimizationnot ESLint
  • Product adoptionnot ESLint
  • Customer journey mappingnot ESLint
  • A/B testing analysisnot ESLint

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

ESLint

  • Slow performance on large codebases compared to newer tools like Oxlint and Biome
  • Complexity in configuration from scratch, particularly for TypeScript support
  • Limited built-in TypeScript support, requiring separate parsers and coordination with new TypeScript features

Heap

  • No built-in A/B testing or feature flags; requires integration with separate tools for experimentation
  • Group analytics and advanced features require a sales conversation, not self-serve
  • Cloud-only deployment; no self-hosted option for data security or compliance requirements
  • Session replay lacks developer debugging tools compared to PostHog
  • Pricing for Growth and Pro plans requires direct sales contact; no transparency on how pricing scales

Pricing, plan by plan

ESLint

Free

No published plan breakdown. See the ESLint review.

Heap

Free
  • FreeFree
    • Up to 10,000 monthly sessions
    • Basic charts
    • 6 months data history
  • Growth$undefined/custom
    • Custom session pricing
    • Sense AI assistant
    • 12 months data history
  • Pro$undefined/custom
    • Custom session pricing
    • Account analytics
    • Engagement matrix
  • Premier$undefined/custom
    • Custom session pricing
    • Data warehouse integration
    • Unlimited projects

Which should you pick?

Choose ESLint if

  • You want to start without paying.
  • You work on Browser-based JavaScript, Node.js, Any JavaScript environment.
ESLint review

Choose Heap if

  • You need autocapture.
  • You want to start without paying.
  • You work on Web, iOS, Android.
  • You also want retroactive analytics.
Heap review

Questions people ask

Is ESLint or Heap better?
Neither clearly leads. ESLint starts at Free and Heap at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, ESLint or Heap?
ESLint starts at Free and Heap at Free.
Does ESLint or Heap run on more platforms?
ESLint runs on Browser-based JavaScript, Node.js, Any JavaScript environment. Heap runs on Web, iOS, Android.
Can I use ESLint for free?
Both have a free tier, so you can try either at no cost before committing.
What is ESLint best used for?
ESLint is most often used for statically analysing javascript and jsx to find problems before runtime, automatically fixing issues with syntax-aware rewrites, enforcing a consistent code style across a team, running as a ci step to block non-conforming code. Of those, statically analysing javascript and jsx to find problems before runtime and automatically fixing issues with syntax-aware rewrites are not what Heap is typically brought in for.
What can ESLint do that Heap cannot?
Heap covers Autocapture, Retroactive analytics, Session replay, Funnel analysis.

Answered from the vendors’ own pages

ESLint: Does ESLint automatically fix code issues?

Many problems ESLint finds can be automatically fixed via the --fix flag. ESLint fixes are syntax-aware so you won't experience errors introduced by traditional find-and-replace algorithms.

Source
Heap: What does Heap's autocapture feature do?

Heap's autocapture is a single code snippet that automatically captures every click, swipe, tap, pageview, and form fill on your website and apps without requiring manual event setup. Once installed, Heap captures the entire digital experience of every user on every platform with no ongoing engineering maintenance needed.

Source
ESLint: How much does ESLint cost?

ESLint is completely free and open-source software maintained by the OpenJS Foundation. The project accepts voluntary donations from sponsors.

Source
Heap: What are Heap's pricing plans and how much do they cost?

Heap offers a Free plan for up to 10,000 monthly sessions. Growth, Pro, and Premier plans use custom session-based pricing that requires contacting sales for a quote. Free includes basic charts and 6 months data history. Growth adds the Sense AI assistant. Pro adds account analytics. Premier adds data warehouse integration and dedicated customer success management.

Source
ESLint: Can I write custom ESLint rules?

Yes. You can develop custom rules that work alongside built-in functionality through ESLint's plugin system, allowing complete customization for your project needs.

Source
Heap: Does Heap include session replay and A/B testing?

Heap includes integrated session replay showing exactly what users did on your site. However, Heap does not include built-in A/B testing or feature flags. Teams requiring these capabilities must use separate tools or integrate with third-party platforms.

Source
Heap: What integrations does Heap support?

Heap supports over 100 integrations connecting to business tools including marketing platforms, CRMs, and data warehouses. This allows insights to reach relevant teams and ensures data flows to other business systems automatically.

Source
Heap: Does Heap offer self-hosting or is it cloud-only?

Heap is cloud-only and does not offer self-hosted options. Organizations requiring on-premises deployment should consider alternatives like PostHog which supports self-hosting alongside its cloud product.

Source
Heap: What is Sense and how does it help with analytics?

Sense Chat is Heap's AI assistant that enables users to access analytics without extensive technical knowledge. It allows teams to ask questions about user behavior and get answers directly without lengthy onboarding or technical expertise, making insights more accessible to non-technical stakeholders.

Source
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