Prepare dev snippets
Encode Base64, escape HTML, generate slugs, and format SQL before sharing snippets.
Free Development Tools
Use regex, cron, SQL, YAML, Base64, schema, slug, color, and CSS helpers without opening a heavy IDE workflow.
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Popular workflows
Validate data contracts
Convert CSV, validate JSON Schema, and generate TypeScript interfaces from sample data.
Tune web implementation details
Test regex, parse cron expressions, convert color formats, and calculate CSS units locally.
Common tasks
- Encode or decode Base64 text.
- Test regex and cron snippets.
- Format SQL and YAML/JSON config.
- Generate slugs, color values, and CSS unit conversions.
Use Fileees Developer Tools when you need a focused browser workflow with clear privacy notes, practical tool order, and no signup for supported local tasks.
Which developer tool should I use?
- Start with the Developer Tools tool that matches your current input, then use related tools only when the next output is clear.
- Prefer browser-local tools for personal files, pasted snippets, and one-off workflows before considering any remote lookup.
- Check the output visually or structurally before sharing it, especially when the source file came from a form, scan, or copied text.
Workflow order
- Identify the exact source format and the result you need.
- Run the smallest matching tool first, then inspect the output before chaining another step.
- Copy or download the final result only after checking privacy notes, limitations, and file quality.
Common mistakes to avoid
- Uploading or pasting sensitive production data without checking whether the tool is browser-local or a marked remote exception.
- Skipping output review because the task looked simple.
- Expecting a lightweight browser tool to replace a full desktop workflow for every edge case.
Limitations before you rely on the result
- Very large files or pasted inputs can be limited by browser memory and device speed.
- Generated output is a practical starting point and should be reviewed before legal, security, or production use.
- Remote network tools are clearly marked exceptions and may contact guarded Fileees functions for public lookups.
All tools in this topic
Base64 Encoder Decoder Encode or decode Base64 text locally Regex Tester Test regular expressions against sample text locally Cron Parser Explain cron schedules and preview upcoming run times CSV JSON Converter Convert CSV to JSON or JSON arrays back to CSV JSON to TypeScript Generate TypeScript interfaces from JSON samples in your browser YAML JSON Converter Convert YAML to JSON and JSON to YAML for config snippets SQL Formatter Format SELECT, JOIN, INSERT, UPDATE, and DELETE SQL statements HTML Escape and Unescape Escape HTML entities or decode escaped HTML text locally JSON Schema Validator Validate JSON data against required fields and simple JSON Schema rules HTML Entities Decoder Encode and decode HTML entities for snippets and content cleanup Slug Generator Generate URL-safe slugs from titles and phrases Color Format Converter Convert HEX colors to RGB and HSL values CSS Unit Converter Convert px, rem, em, and percent values with a configurable base ENV to JSON Convert .env lines to JSON locally JSON to ENV Convert flat JSON objects to .env lines locally Dotenv Sorter Sort .env lines while preserving comments locally HTTP Status Lookup Look up common HTTP status code meanings locally MIME Type Lookup Look up common MIME types and file extensions locally Semver Compare Compare semantic versions locally Regex Escape Helper Escape literal text for regular expressions locally URL Joiner Join base URLs and paths without making network requests
Frequently asked questions
Why is this separate from the old Dev bucket?
The Development category contains general-purpose developer helpers while JSON, Web, Network, Crypto, Docker, XML, and Datetime have their own primary categories.
Are snippets uploaded?
No. Supported development helpers run locally in the browser.
Can I still open old /tools/dev/ URLs?
Yes. Existing category and tool URLs remain available.
Which tools belong here?
General helpers such as regex, cron, Base64, SQL formatting, schema checks, slugs, colors, and CSS units.