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Free Online JSON & Developer Tools

No account required. Common conversions run in your browser, so your input is not uploaded.

01 / Workflows

Start with a real task

Define the data boundary before choosing a tool

Inspect an API response

Format and validate JSON, locate syntax errors, then inspect nested fields in a tree view.

Validate JSON →

Move JSON into a spreadsheet

Define how nested objects, arrays, and types should flatten before creating CSV.

Review the rules →

Migrate configuration

Compare JSON, YAML, and TOML semantics before comments, dates, or types change.

Understand conversion loss →

Generate API types

Generate TypeScript, Java, or Go from JSON Schema or OpenAPI, then compile and test it.

Choose a contract →

02 / Tools

Popular tools

90 published tools; these are common starting points

JSON Formatter & ValidatorValidate JSON syntax and format it with two or four spaces.Processed in your browser · Format conversion

JSON MinifierRemove insignificant whitespace from JSON without changing its data structure.Processed in your browser · Compression

Base64 Encoder & DecoderConvert UTF-8 text to Base64 and decode it back to text.Processed in your browser · Encoding

JSON Tree ViewerExplore JSON as a searchable, collapsible tree.Processed in your browser · Viewer

JSON / XML ConverterConvert JSON and XML with a documented attributes-and-text mapping.Processed in your browser · Format conversion

JSON / YAML ConverterConvert JSON and safe YAML locally with resource limits.Processed in your browser · Format conversion

JSON / CSV ConverterConvert object arrays and CSV with explicit flattening and download safety.Processed in your browser · Format conversion

URL Encoder & DecoderPercent-encode URL components or complete URLs using UTF-8.Processed in your browser · Encoding

Browse all tools

03 / Guides

Understand why results change

View all guides →

JSON and data

Why can large JSON integers lose precision?

Understand JavaScript's safe-integer boundary and how to avoid silently changing API identifiers.

Data conversion

JSON to CSV: how should nested data be represented?

CSV is two-dimensional, so nested objects, arrays, and types need explicit conversion rules.

Data conversion

What can be lost when YAML becomes JSON?

Comments, anchors, tags, and scalar styles have no direct JSON equivalent.

API and code generation

JSON Schema vs. OpenAPI Schema

Both describe JSON, but their goals, supported keywords, and toolchains differ.

Logs and data pipelines

Why NDJSON works well for logs and streams

One JSON object per line supports append, chunking, and per-record processing.

Data formats

Choosing between MessagePack, BSON, and JSON

Compare readability, type range, indexing, ecosystem, and transport cost—not just file size.

04 / Functions

Browse by function

Convert

Tools for format conversion.

View all tools →

JSON Formatter & Validator JSON / XML Converter JSON / YAML Converter JSON / CSV Converter Unix Timestamp Converter JSON / TOML Converter JSON / MessagePack Converter JSON / JSON5 Converter JSON / NDJSON Converter YAML / XML Converter YAML / CSV Converter YAML / TOML Converter

05 / Method

Results with documented boundaries

Tool input is processed locally in the browser and is not stored as site content.
Pages disclose input limits, conversion loss, failure conditions, and update dates.
Guides cite public specifications and connect examples to working tools.

Local processing by default

Every currently published tool runs in your browser. JSONLane does not receive, store, or inspect the content you paste.