DevFiller — Test data form filler Firefox

DevFiller — Test data form filler

Fill any web form with realistic, fictional test data in one click: names, emails, addresses, dates and more, in English, French and Arabic. It never submits the form. Made for developers and QA testers.

Features & Capabilities

DevFiller fills any web form with realistic, fictional test data in one click: names, emails, phones, addresses, dates and more, in English, French and Arabic. It never submits the form. Free, no account, works offline. Built for developers and QA testers who fill the same sign-up flows, checkouts and admin screens again and again. HOW IT WORKS • Open any page with a form and click the DevFiller icon. Every field it recognizes is filled instantly. • DevFiller never submits the form. You review the values and submit when you are ready. • Open the sidebar (right-click the icon and choose "Open DevFiller panel", or press Alt+Shift+F) to see which fields were filled or skipped and why, what each field was recognized as, jump to a field, and undo the last fill. ACCURATE BY DESIGN • Each field is recognized from every clue the page gives: its label, name, placeholder, autocomplete attribute, units such as (mm) or (kg), and the answers a list offers. DevFiller fills a field only when the evidence is strong enough, and shows how sure it is. • It reads the form as a whole: confirmation fields repeat what they confirm, end dates follow start dates, and a phone number follows the country the form asks for. • Values follow each field's rules, and if the site rejects one, DevFiller writes it another way. • Custom switches, checkboxes, dropdowns and rich-text editors built with ARIA roles are filled too. • When the rules aren't sure, a small model built into the add-on suggests a type. It runs offline, and its guesses are marked in the sidebar. • Measured, not guessed: on about 500 real-world forms from public websites (2,500 hand-labelled fields, in English, French and Arabic), DevFiller fills 93.5% of fields with a value that fits and gets 1.9% wrong. • Got a field wrong? Tell DevFiller what it is from the sidebar, and it remembers for that site.

DATA THAT MAKES SENSE • 46 field types: names, usernames, emails, phones, addresses, companies, job titles, dates, numbers, messages and more. • Values fit together: the username and email match the generated name, and the address and phone number come from one country: the United States, France or Algeria (69 wilayas and real communes). • Measurements sized for their unit, and order or invoice numbers that look real. • Repeatable data: type a seed to get exactly the same values on every fill. • Recognizes labels in English, French and Arabic, and generates data in any of the three languages. • Respects input types, length limits, min/max values and dropdown options.

YOU STAY IN CONTROL • Custom values: map a label such as "Project code" to an exact value such as "PRJ-001". • Exclusions: leave search bars, navigation and any field you choose untouched, on every site or just one. • Card fields get sandbox test cards, never real ones: pick a successful, declined, insufficient-funds, expired-card or incorrect-CVC card in the settings, or leave card fields empty. One-time codes, bank fields and consent boxes get values that read as tests (444444, a bank account of 4s, boxes ticked); exclude any field you want left alone. File uploads are skipped. Password fields stay empty unless you turn on test passwords.

OPTIONAL AI FOR UNUSUAL FIELDS Fields the local generator doesn't recognize can get relevant suggestions from Groq or Google Gemini, using your own API key. This is off by default, and Firefox asks for your consent before it's turned on. Only field descriptions (labels, names, placeholders and limits) are sent, never the values you type, the page address or the page content. Without a key, everything runs locally.

PRIVACY No account, no DevFiller server, no analytics. Settings stay in your browser.

Website and docs: https://www.devfiller.com Source code (MIT): https://github.com/gouderhaithem/devfiller

User Growth & Download Statistics

Manifest V3 Add-on
By:
Gouder Haithem
Daily users:
1
Version:
1.2.0 Last updated: 2026-10-06
Version code:
6538834
Creation date:
2026-10-03
Firefox add-on GUID:
devfiller@devfiller.com
Firefox add-on numeric ID:
3085622
Firefox on Android:
Yes
Risk:
Low risk impact High risk likelihood
Permissions:
Host permissions:
  • https://generativelanguage.googleapis.com/*
  • https://api.groq.com/*
Size:
371.07KB
Email:
go*****@gmail.com Email from linked listing: Chrome
Website:
Privacy policy:
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-11-08
Compare stats and ranking:

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:
Gouder Haithem
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/devfiller/
Email:
go*****@gmail.com Email from linked listing: Chrome
Website:
https://www.devfiller.com/support/

Is DevFiller — Test data form filler Safe?

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.
Low risk impactLow risk impact

DevFiller — Test data form filler requires very minimum permissions.

Risk impact analysis details
  • Low Request access to the following domains: generativelanguage.googleapis.com, api.groq.com
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.
High risk likelihoodHigh risk likelihood

DevFiller — Test data form filler is recently added, and hasn't been around long enough for us to gather enough data to accurately assess its risk level.

Risk likelihood analysis details
  • High This extension has low user count. Unpopular extensions may not be stable or safe.
  • Medium **** ********* *** ******* ** *** **** * ******* *** ******* *** *** ** ****** ** *****
  • Medium **** ********* *** ***** ** *** **** * ******* *** ********** *** *** ** ****** ** *****
Extension Guard
Extension Guard

Discover every extension in use, analyze risks, and enforce blocking policies with Extension Guard

Secure Your Browser
Included with Pro and Premium

Look closer at the risk signals

Review the full analysis to understand the factors behind this extension’s risk assessment.

View the full analysis with Pro

Risk signals support your investigation; they are not a guarantee of safety.

Best DevFiller — Test data form filler Alternatives

Here are some Firefox add-ons that are similar to DevFiller — Test data form filler: