The Web Developer Form Filler alternative for when one saved value isn't enough

Worth saying first, because it's true: for restoring your own values into a form you fill often, it is a clean, fast tool. Set up costs nothing — fill the form, click Save form, and the set is stored against that URL. A keyboard shortcut puts it back. No account, no sign-in, no server: sets live in your browser's local storage, and you can export them as JSON and carry them somewhere else.

It's also current. The version on the Chrome Web Store today is 1.0.14, built on Manifest V3, last updated in March 2025 — so this isn't a case of replacing something that stopped working. And when it fills, it fires real input, change and blur events, which is why it works on React, Vue and Angular apps as well as plain HTML.

The model is: whatever you typed is what you get back. That's the strength and the ceiling. Every fill of a given set produces the same name, the same email, the same phone number — so any test that needs a unique record each run means editing the values by hand before you save them again.

There is a random feature, and it's worth being precise about what it does. You can put a token inside a value — {randomNumber:5}, {randomAlpha:5:10}, {randomAlphanumeric:8} — and it generates a string of random characters of that length. That's genuinely useful for a unique username or reference. It is not realistic data: a random eight-character string is not a name, not a valid email address, and not a German street address. There are three tokens, and none of them know what a field is for.

Three other limits show up in practice. Inputs with no id and no name attribute are skipped entirely, which is common in component-framework apps where fields are wired by ref. Saved sets live in this browser's local storage, so a second machine means exporting and importing JSON yourself. And there's no concept of a row: no way to fill from a spreadsheet, and no way to say which record produced the bug you just found.

Your own data, by the row. Import a CSV, Excel or JSON file as a dataset, map its columns to the form's fields once, and every fill takes the next row — sequentially, with the extension telling you “row 3 of 20”, or at random. One form becomes fifty test cases, and when something breaks you can name the row that broke it. This is the part no saved-value tool does, and it's the reason most people switch.

A rule per field, not a value per field. Saving a form in Fillr captures its structure, then you choose per field: generate realistic data (112 types, locale-aware), pin a fixed value, leave it blank, skip it, or pull it from a dataset column. The fixed-value rule covers everything a saved set does; the other four are what a saved set can't.

Data built to break things. Five test-data modes generate values on purpose that a human wouldn't type: boundary (empty, one character, exactly the limit, one over), malformed, special characters and RTL, and structurally valid card numbers and IBANs. Point them at a field and the edge cases come to you.

One preset across environments. URL patterns like **.example.com/signup match localhost, staging and production with a single saved form, instead of one set per exact URL.

You don't want an account. Fillr fills any form with generated data straight after install, signed out — but saving presets and datasets needs an account, because they live there. If your rule is that a form filler must never involve a login, that's a real difference and it points at them.

You want everything on your own machine. Their sets never leave your browser's local storage. Fillr keeps your presets and datasets in your account so they follow you between machines; the filling itself happens locally and the extension holds no tokens, but the data is stored server-side. Some people want neither.

What you actually need is your own values back. If the job is “put my usual test login into this form, fast, with a hotkey”, a saved set does that in one keystroke and generated data would just get in the way.

You're on Firefox. Neither of us helps you there — both are Chrome Web Store extensions — but it's worth knowing before you switch tools expecting cross-browser support.

Honestly, plenty of people run both: theirs for the handful of forms where the exact same credentials go in every time, Fillr for the forms that need a different record on every run.

Install Fillr and click Fill on any form — one-click fill with all 112 data types is free and needs no account, so you can see the difference between realistic values and random strings before deciding anything.

There's no importer for existing sets, and it's worth being straight about that: their export is a JSON map of the values you typed, which isn't what a Fillr preset is. Re-saving a form takes a few seconds — open it, hit Save, set a rule per field — and you get something a saved set can't be: a form that fills differently, on purpose, every time.

The free plan covers unlimited presets, all 112 generators, and three datasets of 50 rows. Filling from your own datasets, the test-data modes and all 60+ locales are Pro ($6.99/mo or $69/yr), with a 7-day free trial that doesn't ask for a card.