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assertpy VS Fillr.app

Compare assertpy VS Fillr.app and see what are their differences

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Contents:
  1. ยป Base Details
  2. ยป Reviews
  3. ยป Alternatives

assertpy logo assertpy

A straightforward assertion library for Python.

Fillr.app logo Fillr.app

Form Filler & Test Data Manager: AutoFill With Data You Control
  • assertpy Landing page
    Landing page //
    2022-11-06
  • Fillr.app Capture Once, Fill Forever
    Capture Once, Fill Forever //
    2026-06-26
  • Fillr.app You Decide Every Field
    You Decide Every Field //
    2026-06-26
  • Fillr.app Fill From Your Own Data
    Fill From Your Own Data //
    2026-06-26
  • Fillr.app Speaks +60 Languages
    Speaks +60 Languages //
    2026-06-26
  • Fillr.app Fill Forms With One Click
    Fill Forms With One Click //
    2026-06-26

Fillr is a form filler and test data manager for Chrome โ€” for when it matters what goes into every field. Save any form as a preset with a rule per field, fill it from your own CSV or Excel rows, and manage all your test data in one place. Realistic generated data (110+ types, 60+ languages) is built in โ€” but you decide where it goes.

Anyone can spray random values into a page. Fillr is for when the data has to be right.

๏ฟฝ EVERY FIELD, YOUR RULES โœ“ Capture any form once and save it as a reusable preset โœ“ Set a rule per field: Generate, Fixed value, Blank, Skip, or Dataset column โœ“ Presets auto-match pages by URL pattern โ€” the right preset surfaces the moment you land on the page (with a picker when several match) โœ“ Preview the fill before you run it โœ“ Unlimited presets, free

๏ฟฝ FILL FORMS FROM YOUR OWN DATA (Pro) โœ“ Link a dataset to a preset, map columns to fields, and fill row by row โ€” sequential with a "row 3 of 20" readout, or random โœ“ Run 50 test cases through the same checkout without typing a single value โœ“ Your edge cases, your real records, your regression rows โ€” not random noise

๏ฟฝ๏ธ A REAL TEST DATA MANAGER โœ“ Import CSV, Excel or JSON โ€” or generate sheets of realistic dummy data โœ“ Edit rows in a spreadsheet grid, organize with tags โœ“ Export any dataset to CSV, Excel or JSON

โšก INSTANT FILL, WHEN YOU JUST NEED VALUES One click auto-fills every field with realistic fake data โ€” names, emails, addresses, phones, dates and more. Zero setup, works on any site, one-click Clear when you're done.

๏ฟฝ 60+ LANGUAGES (Pro โ€” English is free) Generate locale-accurate names, addresses and phone numbers in French, German, Japanese, Arabic and dozens more for international testing.

๏ฟฝ๏ธ POINT-AND-CLICK, 100% NO-CODE A side panel plus a draggable floating bar on the page. Fill, clear, capture, switch presets โ€” no scripts, no selectors, no JSON to edit.

assertpy

Website
github.com
Pricing URL
-
$ Details
-
Platforms
-
Release Date
-
Categories
#Testing #Python
Edit details

Fillr.app

Website
fillr.app
Pricing URL
Official Fillr.app Pricing
$ Details
freemium $9.99 / Monthly
Platforms
Web (Dashboard) Chrome
Release Date
2026 June
Edit details

assertpy features and specs

  • Fluent API
    Assertpy offers a fluent API that makes assertions more readable and expressive, enabling developers to write assertions in a natural language style that is easy to understand.
  • Chainable Assertions
    It allows for chainable assertions, enabling multiple checks to be performed in a single line of code, thereby reducing verbosity and enhancing clarity.
  • Comprehensive Assertion Methods
    The library provides a wide range of built-in assertion methods, catering to various types of data validations, such as checking for size, type, value, and more.
  • Extensibility
    Assertpy supports extending its functionality by defining custom assertions, allowing developers to tailor it to their specific needs.
  • Pythonic
    Designed with Pythonic principles in mind, Assertpy fits seamlessly into Python projects, enabling idiomatic and consistent code style.

Possible disadvantages of assertpy

  • Learning Curve
    Developers new to the library may encounter a learning curve due to the distinct approach of using fluent and chainable assertions as opposed to traditional methods.
  • Limited by Python Version
    The library may have limitations in terms of compatibility with older versions of Python, requiring users to ensure their environment is up-to-date.
  • Performance Overhead
    The additional abstraction layer introduced by a fluent interface might introduce some performance overhead, especially in performance-critical or resource-constrained environments.
  • Less Community Support
    Compared to more established testing libraries, Assertpy might have less community support and fewer resources available for resolving issues or getting help.
  • Dependency Management
    Using a third-party library introduces additional dependencies to manage, which could complicate project maintenance and compatibility.

Fillr.app features and specs

  • Presets
    Capture any web form as a reusable preset โ€” refill in one click
  • Filling Rules
    Per-field fill rules: generated data, fixed value, your own data, or skip
  • Datasets
    Datasets module: build, generate, or import rows of test data
  • Your Data
    Fill forms with your own imported data, not just fake values
  • Bulk Data Generation
    Use presets schema to generate bulk of data
  • 60+ locales
    60+ locales for realistic, region-specific test data

Analysis of assertpy

Overall verdict

  • assertpy is a well-regarded, lightweight assertion library for Python that provides a fluent, chainable API for writing readable and expressive test assertions, making it a solid choice for improving test clarity.

Why this product is good

  • Offers a fluent, chainable assertion syntax that makes tests more readable and self-documenting
  • Comprehensive built-in assertions for strings, numbers, lists, dicts, files, dates, and more
  • Produces clear, descriptive failure messages that speed up debugging
  • Lightweight with minimal dependencies and easy to integrate into existing test suites
  • Framework-agnostic, working seamlessly with pytest, unittest, and other test runners
  • Actively maintained open-source project with good documentation and community support

Recommended for

  • Python developers who want more readable and expressive test assertions
  • Teams using pytest or unittest looking to enhance assertion clarity
  • Projects that value descriptive failure messages for faster debugging
  • Developers coming from fluent assertion libraries in other languages (like AssertJ or Chai)
  • QA engineers and testers writing maintainable, self-documenting test code

Analysis of Fillr.app

Overall verdict

  • Fillr.app appears to be a form-filling automation tool designed to save time by auto-completing online forms, applications, and repetitive data entry tasks. Based on available information, it offers a convenient solution for reducing manual typing, though users should verify current features, pricing, and security practices directly on their site before committing.

Why this product is good

  • Automates repetitive form-filling tasks to save time
  • Reduces manual data entry errors
  • Likely offers browser extension or integration for ease of use
  • Can store commonly used information for quick access across multiple sites

Recommended for

  • Job seekers filling out multiple online applications
  • Professionals who frequently complete online forms
  • Small business owners handling repetitive data entry
  • Users looking to streamline online registration and checkout processes

Category Popularity

0-100% (relative to assertpy and Fillr.app)

assertpy

Fillr.app

Testing
100 100%
Testing
0% 0
Web Forms
0 0%
Web Forms
100% 100
Python
100 100%
Python
0% 0
Chrome Extensions
0 0%
Chrome Extensions
100% 100

Questions & Answers

As answered by people managing assertpy and Fillr.app.

What makes your product unique?

Fillr.app's answer:

It leads with control, not random fill. Capture any web form as a reusable preset, set per-field rules (generated, fixed, your own data, or skip), and refill in one click โ€” plus a built-in Datasets module to build, generate, and export test data. A form-filler and test-data manager in one, no code.

Why should a person choose your product over its competitors?

Fillr.app's answer:

Fake Filler only sprays random data; Mockaroo generates data but can't fill forms. Fillr does both โ€” and lets you fill with your own data, with reusable presets, per-field control, and 60+ locales. No scripts.

How would you describe the primary audience of your product?

Fillr.app's answer:

QA engineers and developers who repeatedly test web forms and need realistic, controllable test data. Demo and sales engineers are a natural secondary audience.

Which are the primary technologies used for building your product?

Fillr.app's answer:

Next.js 15, React 19, and TypeScript dashboard; a Manifest V3 Chrome extension built with Vite and supabase for backend

User comments

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What are some alternatives?

When comparing assertpy and Fillr.app, you can also consider the following products

grappa - grappa is an declarative, verbose, and expressive assertion library for Python.

QuickForm - Autofill Forms - Chrome extension to autofill forms easier and faster.

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