# Format & validate data

> Browser-only file conversion. Selected files are processed on this device and are not uploaded to a conversion server.

Source: https://localconverter.tech/format-data

Check JSON, XML or YAML syntax and create readable formatting, a compact representation or a validation report. Use it to inspect a small configuration file or prepare cleaner text for review. Syntax validation does not establish that values match an application’s schema, so review the actual data requirements separately.

## Useful tasks

- Pretty-print a compact JSON response
- Check YAML syntax before editing
- Create a compact XML copy for an integration

## Steps

1. **Provide the data text**: Upload JSON, XML, YAML or text, or paste the content into the page. Keep the source within eight megabytes and choose its actual syntax.
2. **Choose the result mode**: Select readable formatting, compact formatting or a validation report. Choose the mode according to whether you need revised text or a syntax-check result.
3. **Parse and generate output**: Run Create result so the parser checks the selected syntax. Malformed source is rejected; successful validation creates a JSON report with the syntax and parsed root type.
4. **Check meaning before reuse**: Download and inspect the result in a text editor or destination application. Confirm values and structural expectations, since a valid parse does not establish application-level correctness.

## Settings

- **Syntax**: Choose syntax according to the result you need. Available choices: JSON; XML; YAML. The initial selection is JSON.
- **Result**: Choose result according to the result you need. Available choices: Readable formatting; Compact formatting; Validation report. The initial selection is Readable formatting.

## Readable JSON for debugging

A compact JSON response is difficult to inspect during debugging. Select JSON and readable formatting, then create the output. Open the formatted copy to follow nested fields and arrays, while separately checking whether those fields match the application’s expected response contract.

## Check the result

Choose a file or enter text where available. Review the settings, create your result and download the new copy. Processing stays on this computer. Input and expansion limits apply; originals are never overwritten. Open the saved output in the app or workflow where you plan to use it. Check one representative result before repeating the same settings with more files. The original files stay unchanged.

## Limits

- Files are processed on this device. Browser memory and engine-specific limits apply. Save results before reloading.
- Processing stays on this computer. Input and expansion limits apply; originals are never overwritten.
- Upload one file with a combined size of at most 100 MB. The completed output must fit within 200 MB.
- Pasted text and uploaded text have operation-specific UTF-8 byte limits. Productivity tools accept up to 1 MiB (1,048,576 bytes); non-ASCII characters can use several bytes each. If a file is selected, it takes priority over pasted text.
- Selections and completed jobs stay available while you navigate inside this tab. Use My files to revisit results. Reloading or closing the tab clears the workspace; download results you want to keep first.

## Questions

### Does validation check a JSON Schema?

No. The report indicates that the selected syntax parsed successfully and identifies the root type. It does not check a JSON Schema, business rule or application-specific configuration contract, which needs a separate suitable validation step.

### Does compact formatting change data values?

The tool parses and serializes the data in a compact representation. Values should be reviewed, especially when format-specific parsing rules affect types, and original comments or cosmetic source formatting should not be expected to remain unchanged.

### How is mixed-content XML handled?

For XML containing interleaved text and elements, the formatter avoids adding indentation that would change meaningful text spacing. The result can therefore remain less visibly indented than a simple element-only XML document in readable mode.

### Can it automatically repair malformed files?

No. Invalid JSON, XML or YAML produces a parse error rather than a guessed repair. Correct the source intentionally, including quotation marks, delimiters or indentation as appropriate, then rerun the syntax check or formatting operation.

### Does Format & validate data upload files to another service?

Processing runs in this browser, on your device. Files and pasted input are not uploaded to a conversion server. The website and required engine assets must load first; large operations depend on available device memory.

### Can I continue after changing pages?

Selections and completed jobs stay available while you navigate inside this tab. Use My files to revisit results. Reloading or closing the tab clears the workspace; download results you want to keep first.

## Related guides

- [Clean CSV & delimiters](https://localconverter.tech/clean-csv.md)
- [JSON · XML · TOML · YAML](https://localconverter.tech/structured-data.md)
- [File checksum](https://localconverter.tech/file-checksum.md)
- [QR & barcode maker](https://localconverter.tech/create-code.md)
- [JSON to CSV](https://localconverter.tech/json-to-csv.md)
- [JSON to TSV](https://localconverter.tech/json-to-tsv.md)