TOML to JSON Converter
Turn a TOML config into pretty-printed JSON in your browser — ideal for APIs, scripts, and tooling that speak JSON.
Structured JSON from a TOML config — pretty-printed in your browser.
Choose a file or drag and drop
Drop your TOML file here or
Choose file · Drag & drop · Public file link
- Processed on your device
- No conversion file stored on our servers
- Maximum file size: 100 MB
Conversion runs in your browser. Files are not uploaded to Format Convertly servers.
Processed on your device
No conversion file stored on our servers
Conversion Settings
Customize the output to match your needs.
Convert Quality
92%Quality slider applies when the target is JPG, WebP, or AVIF.
Output
Output options for this format are applied automatically during browser conversion. Drop your file above to begin.
Advanced settings
Additional Options
How to Convert TOML to JSON
Add your TOML
Drop a TOML file into the browser panel. Nothing is sent to a remote queue.
Confirm settings
Review optional quality/size settings, then confirm JSON as the output.
Download JSON
Convert locally and download the JSON file when processing finishes.
Why Convert TOML to JSON?
Private by design
TOML → JSON runs in your browser. Files are not uploaded to a remote conversion queue.
Ready for the next step
Convert when a site, editor, or teammate expects JSON instead of TOML.
Preserve detail
JSON: none or container. Typically lossless or lightly transformed for editing and archival use.
Wide compatibility
TOML is commonly used for Cargo and Rust tooling and Modern CLI app config.
TOML vs JSON
A quick side-by-side before you convert — deeper comparison lives on the full guide.
| Feature | TOML | JSON |
|---|---|---|
| Kind | structured data | structured data |
| Compression | none | none or container |
| Lossy / lossless | Lossless / not lossy | Lossless / not lossy |
| Transparency | Not supported / N/A | Not supported / N/A |
| Best for | Cargo and Rust tooling; Modern CLI app config | REST API bodies; App configuration (package.json and friends) |
| Typical size | Tiny for most configs | Compact; pretty-print increases size for readability |
| Browser / web support | Convert privately in Format Convertly; open in any text editor | Native JSON.parse / fetch; not a document viewer format |
| Compatibility | First-class in Rust/Cargo and many modern CLIs; convert to JSON when a web service or legacy tool only accepts JSON | Native in JavaScript; first-class libraries in every major language |
Choose TOML when…
- Cargo and Rust tooling
- Modern CLI app config
- Human-edited service settings
- Replacing ad-hoc INI with clearer types
Choose JSON when…
- REST API bodies
- App configuration (package.json and friends)
- NoSQL document exports
- Interchange between services
What happens to quality?
TOML: TOML compression: none. Lossless (or non-destructive packaging) keeps reconstructable data — size savings come from packing efficiency, not throwing detail away. Typical size profile: Tiny for most configs. Quality note: Lossless structured text for configuration JSON: JSON compression: none or container. Lossless (or non-destructive packaging) keeps reconstructable data — size savings come from packing efficiency, not throwing detail away. Typical size profile: Compact; pretty-print increases size for readability. Quality note: Exact for supported literal types; no native date type Structured JSON from a TOML config — pretty-printed in your browser.
Tip
Keep an original copy of your TOML file if you may need to reconvert later.
When should I use JSON?
JSON: JSON is the default payload for web APIs and many app configs. It maps cleanly to programming types. Convert JSON to CSV when analysts need a flat table, or to YAML when humans must edit the same data as config. Best for REST API bodies and App configuration (package.json and friends).
JSON format guide →When should I keep TOML?
Keep TOML when you still need to edit or when it already matches your audience. TOML aims for obvious semantics: tables, typed values, and fewer surprises than YAML edge cases. Convert to JSON when an API or web tool only accepts JSON.
TOML format guide →TOML · JSON
Related converters TOML
Related converters JSON
Frequently Asked Questions
More on quality loss: conversion quality guides · problem-solution guides
Does converting TOML to JSON reduce quality?
Often no for lossless or remux-style paths. Quality drops when you re-encode with lossy settings, downscale, or flatten features like transparency.
Can you recover quality after converting?
Not from a lossy output alone. Return to the original master (or a better source). Converting to a lossless format does not resurrect discarded detail.
Where can I learn more about conversion quality?
Browse Format Convertly’s Quality guides for topics like whether conversion reduces quality, JPG↔PNG myths, WebP/MP3/MP4 tradeoffs, recovery limits, and generational loss — each links to the right converter.
Are comments kept?
JSON has no comments. Values and structure are preserved; TOML comments are dropped.
Is my config uploaded?
No. Parsing and JSON writing happen in your browser.
Can I convert back?
Yes — use /converters/json-to-toml when the JSON root is an object.
What is a TOML file?
TOML is a minimal, typed configuration file format popular with Rust and modern CLIs. TOML aims for obvious semantics: tables, typed values, and fewer surprises than YAML edge cases. Convert to JSON when an API or web tool only accepts JSON.
What is a JSON file?
JSON is a lightweight text format for structured data (objects, arrays, strings, numbers, booleans, null). JSON is the default payload for web APIs and many app configs. It maps cleanly to programming types. Convert JSON to CSV when analysts need a flat table, or to YAML when humans must edit the same data as config.
Ready to Convert Your Files?
TOML to JSON privately in your browser.