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Query String Generator

Turn a JSON object into a URL query string.

Updated

This tool runs in your browser. No account or signup is required.

Common Query String Generator tasks

Developers typically reach for this page when they need to build a URL query string from parameters; convert JSON to query string; generate encoded URL parameters. The tool is built for quick, practical work rather than a generic demo.

What matters in a query string generator workflow

When developers compare online tools for this job, the useful capabilities tend to center on JSON/key-value input, repeated keys, percent encoding, copy. This page keeps those practical needs in mind while linking to related tools when a different workflow is a better fit.

What is Query String Generator?

Query String Generator takes a flat JSON object and prints it as an encoded key=value query string.

What problem does it solve?

Long URLs with many parameters are hard to read, and building encoded query strings by hand invites mistakes.

How to use Query String Generator

  1. Paste a JSON object.
  2. Press Process.
  3. Copy the query string.

Example

Input

{"q":"json","page":2}

Output

q=json&page=2

What you can do with Query String Generator

  • Build a query string
  • JSON to query string
  • Generate URL parameters

Common use cases

  • Debugging tracking and filter parameters
  • Building test URLs for an API
  • Checking what a redirect URL really carries

Related developer tasks

  • Build a query string
  • JSON to query string
  • Generate URL parameters

JSON to query string example

{"q":"hello world","page":"2"}

// output
q=hello+world&page=2

What the generator expects

  • A flat JSON object. Strings and numbers work best.
  • Spaces become + and special characters are percent-encoded.
  • Nested objects become [object Object], and arrays are joined with commas, so flatten your data first.
  • The question mark is not added, so put ? in front yourself.

Related: Query String Parser, URL Encoder, JSON Validator

Query String Generator FAQ

Does it support nested objects?

Use a flat object. Nested values are not expanded into separate parameters.

Is my data sent to a server?

The processing runs in your browser, so what you paste into the tool is not uploaded for processing. As with any tool, avoid pasting live secrets you cannot afford to leak.

Why do I see Error processing input?

The input is not valid JSON. Check it with the JSON Validator.

Looking for something else? Browse all developer tools.

onlinedevelopertool.com is a collection of 54 free, browser-based utilities for the small jobs that interrupt real work: formatting a JSON response, decoding a token, converting a timestamp, generating a UUID or checking a hash. Each tool has its own page with a short explanation, a worked example and answers to common questions, so you can use it and learn what it does at the same time.

There is no account to create and nothing to install. Tools run in your browser, so the text you paste is processed on your own device. The one exception is the Website Status Checker, which sends a request from your browser to the address you enter.

Three steps: paste your input, click the tool, copy the result, all inside your browser
Popular developer utilities: JWT decoder, UUID generator, Base64 decoder, SHA-256 hash, regex tester and timestamp converter

What you can do here

  • JSON Tools

    Format, validate, beautify and minify JSON, generate C#, TypeScript, Java, Python, Go, PHP and Kotlin models from it, or convert between JSON, YAML and CSV.

  • Encoders & Decoders

    URL, Base64 and HTML encoding and decoding, plus a JWT decoder for reading token claims.

  • Generators & Hashes

    Generate UUIDs and JWTs, validate UUIDs, and create MD5, SHA-256 and SHA-512 hashes.

  • Web Tools

    Timestamps, color codes, query strings and cron expressions - the small things web work keeps throwing at you.

  • Text & Data

    Format XML and YAML, count text, change case, make slugs, test regex, diff two texts and convert number bases.

  • Website Checking

    Check whether a website or URL is reachable from your browser.

Quick developer reference

  • JSON

    Keys and strings must use double quotes, and trailing commas and comments are not allowed. Those are the three most common reasons a payload fails to parse.

    Validate JSON

  • JWT

    A JSON Web Token is three Base64URL parts joined by dots: header, payload and signature. Decoding shows the claims but does not prove the token is genuine; only signature verification does.

    Decode a JWT

  • Base64

    Base64 is an encoding, not encryption. Anyone can reverse it, and it makes data roughly one third larger, so never use it to hide secrets.

    Decode Base64

  • UUID

    A version 4 UUID is made of random bits and written as 8-4-4-4-12 hexadecimal characters. Collisions are astronomically unlikely, which is why they work well as identifiers.

    Generate a UUID

  • Timestamps

    A Unix timestamp counts time since 1 January 1970 UTC. Ten digits usually means seconds and thirteen digits usually means milliseconds.

    Convert a timestamp

  • Hashes

    MD5 is fine for quick checksums but is not safe for security. Prefer SHA-256 or SHA-512, and remember that hashing is one-way and is not encryption.

    Create a SHA-256 hash

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