BackstopJS vs Needle
BackstopJS
github.comNeedle
github.comSide by side
| Figure | BackstopJS | Needle |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| macOS | Yes | — |
| Linux | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 1 | 1 |
| Spec score · Visual Regression Testing Software | 8.0 (#11) | 8.1 (#9) |
| Installation | It can be installed globally or locally with npm, used as a standalone CLI, or required from a Node.js app. | The documentation installs Needle with pip and lists Selenium as a dependency to install. |
| Integrations | The README describes CI reporting in JUnit format and integration with build systems such as Jenkins, Travis, and gulp. | The README demonstrates a nose test case using Selenium to open a web page and check an element screenshot. |
| License | GitHub identifies the project as MIT licensed. | The package metadata classifies Needle under the OSI-approved BSD License. |
| Purpose | BackstopJS automates visual regression testing of web apps by comparing screenshots over time. | Needle tests CSS and other web visuals by comparing screenshots with known good screenshots. |
| Security | The README recommends matching the Docker container user to the local environment to improve security and avoid file ownership problems. | GitHub reports that the project has no SECURITY.md policy and no published security advisories. |
Plans
In their own words
BackstopJS
BackstopJS is a free, MIT-licensed tool for visual regression testing of web applications. It captures screenshots and compares them with reference images over time. An in-browser report shows reference, test and visual-difference views, with additional CLI and JUnit reports. BackstopJS supports Puppeteer and Playwright; Playwright can use Chromium, Firefox or WebKit. Scenarios can script clicks, scrolling, hovering, key presses and cookie state. Captures can cover a full document, viewport or selected DOM elements at configured viewport sizes. The documented workflow uses `backstop init`, `backstop test` and `backstop approve` to configure tests, compare captures and update references. Installation works globally or locally through npm, as a standalone CLI or from a Node.js app. CI reporting and integrations include Jenkins, Travis and gulp. Docker can reduce rendering differences, though Chrome Headless in Docker needs substantial memory.
Needle
Needle is an open-source Python testing library for checking rendered website visuals and layout. It captures selected page areas and compares them with baseline screenshots, helping identify visual changes in CSS, fonts, images, and SVGs. It also tests calculated CSS values and HTML element positions. Needle works with Selenium and nose, and documentation describes installing it with pip after Selenium. Browser-driver options include remote, PhantomJS, Firefox, Chrome, Internet Explorer, Opera, and Safari; NeedleFirefox is the default. PIL is the default screenshot engine, with PerceptualDiff and ImageMagick available as alternatives. PerceptualDiff and ImageMagick can create a diff PNG when comparisons fail. Tests can set viewport dimensions for responsive-site checks. Screenshot cleanup after successful tests is optional and disabled by default, while failed-comparison screenshots remain available. Package metadata describes the project as operating-system independent and for developers, while the listed platform is Linux. The repository uses a BSD license. PyPI lists version 0.5.0, released April 2, 2017, as the latest release. Needle is free and has no paid plan.