ToolMars Collection

Free Online Tools.

Developer utilities, SEO tools, and calculators — all free, all browser-based. Your data never leaves your device.

All Available Tools

Browse our complete catalog of browser-based utilities.

Blog Image Resizer

Automated center-crop asset optimizer. Perfectly handles 1200x675 Featured banners and 800x450 H2 post images simultaneously.

SEOOpen

FeaturedMost Used

Batch Image Converter

Convert PNG, JPG, WebP and more — all at once, right in your browser. No uploads, no waiting.

UtilityOpen

FeaturedNew

Advanced Image Cropper

Crop image regions and configure output dimensions simultaneously. Zero quality loss, handled completely in-browser.

UtilityOpen

FeaturedPopular

Image Compressor

Shrink JPEG, PNG and WebP files without losing quality. Adjust compression level and download individually or as a ZIP.

UtilityOpen

FeaturedPopular

JSON Formatter

Paste messy JSON and get it back clean, indented, and error-free in one click.

DevelopmentOpen

SEO

Slug Generator

Turn any title into a clean, URL-friendly slug for better SEO — instantly.

SEOOpen

Hot

QR Code Designer

Generate high-resolution QR codes with your brand colors. Download as PNG instantly.

UtilityOpen

Universal QR Reader

Scan any QR code from your webcam or a screenshot — no app needed.

UtilityOpen

Word & Text Counter

Count words, characters, and reading time. Change text case in seconds.

UtilityOpen

FeaturedPopular

SERP Preview Tool

See exactly how your title and meta description look in Google before you publish.

SEOOpen

Robots.txt Generator

Build a valid robots.txt visually, test crawler rules, and block AI scrapers easily.

SEOOpen

Schema Markup Generator

Create valid JSON-LD structured data for articles, products, and web apps — no code needed.

SEOOpen

Redirect Map Compiler

Paste old and new URLs and get a ready redirect file for Nginx, Apache, or Next.js.

DevelopmentOpen

Image SEO Sanitizer

Rename image files into SEO-friendly slugs and strip hidden EXIF data — all locally.

SEOOpen

Popular

Mortgage Calculator

Calculate your monthly payment, total interest, and full amortization schedule.

CalculatorsOpen

Trading P&L Calculator

Track your average buy price, calculate profit or loss, and plan your next trade.

CalculatorsOpen

Age Calculator

Find your exact age in years, months, days, and hours — and see upcoming milestones.

CalculatorsOpen

CGPA & GPA Calculator

Enter courses, credit hours, and grades to get your semester GPA and cumulative CGPA.

CalculatorsOpen

New

Square Footage Calculator

Calculate square footage easily for rooms, flooring, and gardens. Supports rectangles, circles, triangles, and material waste factor.

CalculatorsOpen

Custom Utilities

Can't find the tool you need?

We are constantly building new utilities. Let us know what you're looking for, and we might build it next! We read and build every valid request.

What is ToolMars?

ToolMars is a free collection of browser-based tools for developers, students, and content creators. Every tool runs entirely in your browser — your data never gets sent to a server. There are no accounts, no paywalls, and no ads covering the workspace.

What tools are available?

Developer utilities — JSON formatter, slug generator, redirect compiler, blog image resizer, and more.
SEO tools — SERP preview, robots.txt generator, schema markup builder, and image filename sanitizer.
Image tools — advanced image cropper, batch image converter, image compressor, QR code designer and reader.
Calculators — mortgage calculator, GPA/CGPA calculator, age calculator, and trading P&L tracker.

Are these tools really free?

Yes, every tool on ToolMars is completely free with no usage limits. No premium tiers, no feature locks, no signup forms. The tools work the same whether you use them once or a hundred times a day.

Is my data private?

Every tool processes your data locally inside your browser. Nothing you paste, upload, or type gets sent to ToolMars servers — because there are no servers involved. This is especially important for tools like the JSON formatter, image converter, image cropper, image compressor, and CGPA calculator, where you might be working with sensitive information.