Spoold is a free, privacy-first developer toolbox. Paste into the Magic Box and it detects JSON, HTML, JWT, curl, OpenAPI, CSV, timestamps, and more—then suggests the best tool. You can also browse the full catalog by category. No sign-up is required.

Is Spoold free to use?

Yes. Core tools are free. Heavy work runs in your browser so your payloads are not processed on Spoold servers for formatting, decoding, and similar utilities.

Is my data safe with Spoold?

Tool processing for supported client-side utilities happens in your browser. Encrypted share links are designed so only people with the link can read the payload. Review the Privacy Policy for details on local storage, analytics, support, and third-party services.

What tools are available?

Spoold ships 67+ tools including JSON formatter and diff, JSON Schema validation, YAML and TOML converters, HTML and Markdown preview, JWT decode and sign, OpenAPI/Swagger viewer with curl, GraphQL formatter, curl to code and curl compare, certificate viewer, CSV preview, regex tester, Mermaid, code editor, LLM token utilities, QR codes, and many encoding and text utilities.

Yes. Spoold uses optional support and in-layout promotions for its own tools instead of third-party ad placements. You can support development from the Support Spoold page.

Can I use keyboard shortcuts?

Yes. Press Cmd or Ctrl+K to open tool search, use / from the homepage, and use per-tool shortcuts (shown in the UI) such as jj for JSON and hh for HTML where configured.

Spoold

Paste. Detect. Do.

Guides are written by the Spoold Editorial Team and reviewed for practical accuracy against the related tools. Read our Editorial Policy for update and correction standards.

Practical developer guides

Tutorials that turn messy inputs into working tools.

Short, practical guides for JSON, CSV, Docker Compose, regex, URLs, security checks, and SEO workflows inside Spoold.

Articles

Topics

Matching guides

Showing 5 of 39 articles

Data8 min

How to Remove Null and Empty Fields from JSON

Clean JSON objects and API payloads by removing null values, empty strings, empty arrays, and empty objects. Learn safe cleanup rules, examples, and when not to strip fields.

Jun 20, 2026Read

Guide12 min

JSON Diff Online — Compare Two JSON Files, Deep Compare & Visual Diff (Monaco)

Free online JSON diff and JSON compare tool. Paste original and modified JSON, see added/removed/changed paths with semantic deep compare, Monaco DiffEditor, Report/Side/Unified views, export JSON/CSV/TXT, save/share links — ignores object key order, runs entirely client-side with no upload.

May 2, 2026Read

Tutorial9 min

JSON Schema Validator Online: Validate JSON Against a Schema

Learn what JSON Schema is, which drafts matter (4–2020-12), how SchemaStore helps, and how to use a free browser validator for APIs, configs, and package.json.

Mar 29, 2026Read

Tutorial8 min

How to Format JSON Like a Pro: Complete Guide

Master JSON formatting with our comprehensive guide. Learn best practices, common pitfalls, and how to use the JSON Formatter tool effectively.

Jan 2, 2026Read

Data8 min

CSV to JSON Conversion: Complete Guide

Convert CSV to JSON with auto-delimiter detection, table view, and export to JSON, SQL, or Markdown. Best practices, common pitfalls, and how to use the CSV Viewer tool.

Dec 25, 2025Read

Ready to Try Our Tools?

Put these tutorials into practice with our free developer tools. No sign-up required.

Explore Tools