MySpeedGauge

Developer Tools

Free Online Developer Tools

Format, validate, convert, compare, and debug data without sending it to a server. Every tool on this page runs in your browser.

  • Free to use
  • Runs in your browser
  • Privacy-first
  • No account required

  • JSON Formatter

    Format, validate, and explore JSON with a tree view.

    JSON

    Open Tool

  • JSON Diff

    Compare two JSON values and list what changed.

    JSON

    Open Tool

  • JSON to CSV

    Convert an array of objects into a CSV file.

    Converters

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  • JSON to YAML

    Turn JSON values into block YAML.

    Converters

    Open Tool

  • JSONPath

    Query JSON with a small, documented path language.

    JSON

    Open Tool

  • JSON Schema

    Validate JSON against a draft 2020-12 subset.

    JSON

    Open Tool

  • Base64

    Encode or decode UTF-8 text and small files.

    Encoders

    Open Tool

  • JWT Decoder

    Inspect a token header and payload. The signature is not checked.

    Security

    Open Tool

  • URL Encoder

    Encode or decode URLs, query strings, and parameters.

    Encoders

    Open Tool

  • Regex Tester

    Test a pattern, see groups, and preview a replacement.

    Text & Data

    Open Tool

  • Unix Timestamp

    Convert seconds or milliseconds to a calendar time.

    Text & Data

    Open Tool

How to use the hub

  1. Search by name, or choose JSON, Converters, Encoders, Security, or Text & Data.
  2. Open a tool. The search box stays on this page and does not create another URL.
  3. Start with the JSON formatter, the diff checker, or Base64.

Common mistakes

  • Base64 hides nothing. It is not encryption.
  • The JWT decoder does not verify a signature.
  • Pasting a secret into a shared computer still leaves it in that browser tab until you leave the page.

Frequently asked questions