fileview.dev

Alternatives to the popular online JSON editors

7 min read

Written by the maintainer of fileviewer.dev, which is one of the tools listed. Where a competitor is the better answer, it says so.

The right alternative depends on what is wrong with the tool you have: for privacy, pick something that parses in your browser; for large files, pick jq; for a cleaner interface, several options remove the advertising; and for features a tree cannot give you, pick a tool with table, graph and diff views.

Start from the complaint

What is wrong, and what to move to
Your reason for leavingWhat to use instead
My data is confidentialA client-side viewer — fileviewer.dev, or Firefox’s built-in viewer
The file is too bigjq, or a desktop editor built for large files
Too many adsfileviewer.dev, or a browser extension like JSON Formatter
I need more than a treeA tool with table, graph, diff and chart views
I need to transform, not just readjq — no GUI competes on this
I want it in my editorVS Code with its built-in JSON support
I want to share the resultA Gist, or a paste service — client-side tools have nowhere to put it

The options in detail

jq

A command-line JSON processor. It streams rather than loading a whole document into memory, so it is the only option here that handles gigabytes, and its query language does transformations no GUI matches.

Choose it when the file is large, the task is repeatable, or you need to reshape rather than read. Skip it when you do not yet know the document’s shape — a tree view answers that faster than any query.

Firefox’s built-in viewer

Overlooked, and genuinely good. Drag a .json file into Firefox and you get a collapsible tree with a filter box, no extension and no upload.

Choose it when you want zero setup and zero risk. Skip it when you need a table, a diff or a schema check.

VS Code

If it is already open, it is hard to beat: format on save, schema validation via $schema, folding, and multi-cursor editing. Extensions add tree views and JSONPath queries.

Choose it when you are editing rather than reading, or the file is part of a project. Skip it when you want a structural overview of an unfamiliar document — an editor shows text, not shape.

Browser extensions

JSON Formatter and similar extensions intercept JSON responses as you browse and render them automatically. For anyone reading API responses all day, that automatic behaviour beats any tool you have to visit.

Choose it when your JSON arrives over HTTP in a browser. Skip it when you have a file on disk — and weigh that an extension able to read page content is a real amount of trust.

File Viewer

The tool this site is about, so treat this as an argument rather than a review. It parses in your browser, handles JSON, YAML, XML, CSV and Markdown, and offers nine views including a graph, a structural diff and a chart. It needs no account, and the tool itself carries no advertising — though reference pages on the site, including this one, do.

Choose it when the file is confidential, you deal with more than one format, or you want a reading a tree cannot give you. Skip it when the file is enormous — the ceiling is 500 MB and jq is the better tool well before that — or when you need to share the result, which requires a server it deliberately does not have.

How to check a tool’s privacy claim

Every online tool claims to be safe. The claim is checkable in under a minute, and worth checking before you paste anything sensitive into any of them, including this one.

Watch the network
Open developer tools, go to the Network tab, and load a file. Look for a request whose payload is your document. Application code and fonts are expected; your data is not.
Disconnect
Load the page, switch off your network, then load a file. A tool that parses locally keeps working. One that uploads fails immediately. This is the test that cannot be faked by a privacy policy.
Read the source, if there is any
An open-source tool lets you find every place it makes a request. A closed one asks you to take the policy on trust.

Try it with your own fileThen check the network panel.

Questions

What is a good alternative to JSON Editor Online?

It depends why you are looking. For privacy, use a tool that parses in your browser — fileviewer.dev, or Firefox’s built-in viewer. For large files, use jq. For editing within a project, use VS Code. For reading API responses as you browse, use a formatter extension.

Is there a JSON viewer that does not upload my data?

Yes. fileviewer.dev parses entirely in your browser, and Firefox’s built-in viewer never touches a network at all. You can verify either by loading a file with your network disconnected — both keep working.

What is the best free JSON viewer without ads?

The fileviewer.dev application carries no advertising and has no paid tier for viewing, though its reference pages do carry ads. Firefox’s built-in viewer has none at all. Browser extensions such as JSON Formatter are also ad-free, and have the advantage of working automatically on every JSON response you load.

What handles JSON files larger than 100 MB?

jq, because it streams rather than loading the document into memory. Browser tools are bounded by available memory; fileviewer.dev accepts up to 500 MB but jq is the better choice well before that, and the only realistic one in the gigabyte range.

Can I edit JSON online rather than just view it?

Yes — fileviewer.dev embeds the Monaco editor, the same one VS Code uses, with formatting, find and replace, and validation as you type. For anything that is part of a project, though, editing in your own editor keeps the file under version control where it belongs.