data

JSON / YAML / CSV Viewer

View, search, analyze, and convert JSON, YAML, CSV, TSV, and JSON Lines locally in your browser.

Local processing

About your filesFiles and content selected in this tool are processed in your browser and are not uploaded to a Browser Kitty backend.

Operation demo See the basic workflow in a short video.

About this tool

JSON / YAML / CSV Viewer goes beyond pretty-printing and covers the quick inspection work you often need after receiving structured data. JSON and YAML can be explored as trees, while CSV, TSV, and object arrays can be viewed as tables.

It also provides search, column profiling, simple quality checks, JSON Schema inference, and conversion among common formats, making it useful for checking API exports and data-integration files.

Good for

Quickly inspect the structure, missing values, and value patterns in JSON received from an API or external system
Detect CSV encoding and delimiters, then review table columns and data quality
Convert among JSON, YAML, and CSV or generate a starting JSON Schema from the loaded data

What it can do

Key capabilities available in this tool.

Tree view for JSON and YAML
Table view for CSV and TSV
Search, analysis, and quality checks
Convert to JSON, YAML, CSV, and JSON Schema

How to use

Select Open tool and choose or drop a JSON, YAML, CSV, TSV, or JSON Lines file.
Review the detected format, encoding, and delimiter; change the encoding if needed.
Switch among tree, table, formatted text, and analysis views.
Use search and analysis to inspect keys, values, paths, types, missing data, uniqueness, quality warnings, and inferred JSON Schema.
Convert and save the data as JSON, YAML, CSV, or JSON Schema when needed.

Supported

Input: .json / .yaml / .yml / .csv / .tsv / .jsonl / .ndjson.
Encodings: UTF-8, Shift_JIS, and UTF-16LE; UTF-8 and Shift_JIS are detected where practical.
CSV delimiters: detects comma, tab, semicolon, pipe, and similar delimiters.
Currently handles one file at a time, up to 50 MB.

Limitations and notes

The built-in YAML parser targets a common subset and does not fully support custom tags, anchors/aliases, or complex multi-document YAML.
JSON Schema inference is heuristic and should be reviewed before using the result as a production schema.
CSV treats the first parsed record as the header.
Very large or deeply nested data can require more rendering time and memory.

Frequently asked questions

Which file formats are supported?

JSON, YAML, CSV, TSV, and JSON Lines / NDJSON are supported.

Can it read Shift_JIS CSV files?

Yes. It supports UTF-8, Shift_JIS, and UTF-16LE, with practical auto-detection between UTF-8 and Shift_JIS.

Is the loaded data uploaded?

No. Encoding detection, parsing, search, analysis, and conversion run in your browser; the data file is not sent to Browser Kitty.

Can it generate JSON Schema?

Yes. It can infer JSON Schema from the loaded data, but the result is heuristic and should be reviewed before formal use.

Offline version and source code

A self-contained single-HTML build is available on GitHub with no runtime external dependencies. Open it locally to inspect, analyze, and convert data without network access.

View source on GitHub