Yellow Tools library
One useful job at a time.
Explore focused tools with clear inputs, honest limitations, and results designed to be immediately useful.
Creative work, simplified
Make. Measure. Improve.
Design
Practical image and CSS tools for everyday visual work.
Image Resizer
Resize JPG, PNG, and WebP images with clear dimension controls.
Browser-based tool
Image Compressor
Reduce image file size and compare the result before downloading.
Browser-based tool
CSS Gradient Generator
Create linear, radial, and conic gradients with ready-to-copy CSS.
Browser-based tool
SEO
Write, preview, and validate essential search-facing content.
Google SERP Preview
Preview how page metadata may appear in desktop and mobile search results.
Browser-based tool
Robots.txt Generator
Build clear crawl directives and download a ready-to-use robots.txt file.
Browser-based tool
Keyword Density Checker
Analyze pasted text for word and phrase frequency without ranking claims.
Browser-based tool
Business
Straightforward calculators with transparent formulas and assumptions.
Profit Margin Calculator
Calculate profit, margin, and markup without mixing their definitions.
Browser-based tool
ROI Calculator
Calculate net return and ROI with clearly stated assumptions.
Browser-based tool
Break-even Calculator
Estimate the units and revenue required to cover fixed costs.
Browser-based tool
Website
Small utilities for cleaner links, data, and page metadata.
UTM Generator
Generate valid campaign links while preserving existing URL parameters.
Browser-based tool
JSON Formatter and Validator
Validate, format, minify, copy, and download JSON locally.
Browser-based tool
Meta Tag Generator
Generate escaped HTML for essential page and social metadata.
Browser-based tool
Social media
Template-driven helpers for more consistent social publishing.
Hashtag Generator
Combine curated hashtag sets by topic, platform, audience, and reach.
Browser-based tool
Instagram Bio Generator
Create useful bio variations from local templates and your details.
Browser-based tool
Social Media Content Calendar
Build a deterministic weekly or monthly publishing plan.
Browser-based tool