Free Online Tools – Images, PDFs, Text, Code, SEO & Calculators

BigToolSite is a free online tools website with 150+ single-purpose tools for images, PDFs, text, code, design, SEO and everyday calculations. Every tool opens and runs in your browser, needs no account or credit card, and includes a short how-to guide on the same page. There is nothing to install and no trial that expires.

What Kind of Tools Does BigToolSite Have?

BigToolSite began as a small set of SEO utilities and now covers eight categories. The grid above shows a sample of the library, and each category below leads into the rest. Every tool does one job on one page, with no dashboard or multi-step wizard in the way.

Image Tools

Convert between JPG, PNG, WebP, AVIF, HEIC, GIF, BMP, TIFF and ICO, then compress, resize, crop, watermark, remove backgrounds, pick colors or read EXIF data. The Image Compressor processes up to 10 images at once and shows the exact size saved on each file.

PDF Tools

Turn PDF pages into images, build a PDF from a stack of photos, and split or merge documents with no page limits and no watermark stamped on the output. The PDF Converter combines convert, split and merge in one interface.

Text and Writing Tools

Check grammar, spelling, punctuation, passive voice and reading level, then count words, compare two drafts, strip duplicate lines or reshape letter case before publishing. The Readability Test scores your text against Flesch and other standard readability formulas.

SEO Tools

Build and test robots.txt files, trace redirect chains, prepare disavow submissions, generate sitemaps and schema markup, tag campaigns with UTM parameters and preview how a page will look when shared. The Robots.txt Generator builds a valid file with your crawl rules and sitemap line already in place.

Developer and Code Tools

Format, minify and validate HTML, CSS, JavaScript, JSON, XML, YAML and SQL, plus regex testing, JWT decoding, hashing, UUIDs, cron expressions, curl commands and htaccess to nginx conversion. The JSON Formatter validates and pretty-prints JSON with the error line highlighted when parsing fails.

CSS, Color and Design Tools

Generate gradients, box shadows, text shadows, border radii and clamp values, then build color palettes, convert between HEX, RGB, HSL and CMYK, and check designs for color blindness. The CSS Gradient Generator gives you a live preview and copy-ready CSS as you drag the color stops.

Calculators and Converters

Work out percentages, ages, aspect ratios, DPI, file sizes, CPM, CTR, conversion rates, hourly rates and BMI, or convert timestamps, roman numerals and number bases. The Percentage Calculator covers increases, decreases, differences and “what percent of” in a single tool.

Network and Domain Tools

Calculate subnets, CIDR ranges, network masks and broadcast addresses for IPv4 and IPv6, and check DNS records, SSL certificates and domain age. The IP Subnet Calculator returns the usable host range, network address and broadcast address from any IP and mask.

Why Use BigToolSite Instead of the Alternatives?

• No account, ever – No email, no login wall, no verification step between you and the result.
• No paid tier holding features back – There is no premium plan, so no setting is greyed out and no export is capped.
• A how-to guide on every tool page – Each page explains the inputs, the settings and what the output means, so you get a usable result the first time.
• One tool, one job – Tools are built around a single recurring task instead of bundled into a suite you have to learn.
• New tools added regularly – The library grows most weeks, driven by tasks that keep coming up in real work.

How to Use Any Tool on BigToolSite

1. Find the tool – Browse the grid above, load more, or search for the specific job you need done.
2. Add your input – Upload a file, paste your text or type in your numbers. Nothing else is required.
3. Adjust the settings – Most tools have a handful of options such as output format, quality or units, each explained on the page.
4. Save the result – Copy the output, download the file, or download a batch as a ZIP where the tool supports it.

How BigToolSite Handles Your Files and Data

The image tools and PDF tools on BigToolSite run entirely inside your browser using JavaScript and WebAssembly. Your file is never uploaded to a server, which is why a large image converts as fast as your own device can process it. Some tools, including the text generators and a few of the writing checkers, send the values you type to our server to produce a result, and those values are not stored afterwards. No tool on the site requires an account, and none of them keep your input once the job is done.

Who Builds BigToolSite?

BigToolSite is built and maintained by a three-person team that works on websites, content and SEO day to day, which is where most of the tool ideas come from. Every tool is written specifically for this site rather than embedded from a third-party service, and each one is tested against awkward real-world inputs before it goes live. You can read more about how the tools are built on the About Us page.

Pick any tool from the grid above and it works immediately. No signup, no download, no trial period.

Frequently Asked Questions