HoldMyTwist
10 computer file terms explained for beginners
Understand file extensions, formats, pixels, compression and project files. Learn what to check before resizing, converting or sharing a file.
In this guide
Topic
Free tools for files and images
Resize an image, make a QR code or a flowchart, fix JSON and compare CSV files with free tools, plus the file terms these guides use.
Start with the file terms guide if formats, image sizes or compression are new to you. The other guides use those terms.
The browser tools guide covers ten everyday jobs. The rest each go deeper on one tool. Shrink an image with Squoosh, make a QR code and save it as SVG, turn text into an editable draw.io flowchart, find a JSON error with JSONLint and compare two small CSV files by ID.
Read in this order
10 everyday tasks you can do with free browser tools
Compress, resize and export pictures, sketch a diagram and check colour contrast with free browser tools. Includes steps, screenshots and limits.
Make an image smaller for upload with Squoosh
Resize and compress an image for upload with Squoosh. Follow real screenshots, check pixels and file size, and know when a free tool is enough.
Create a free QR code and save it as SVG
Create a direct-link QR code without an account, save the SVG and check the destination before sharing or printing. Includes our verified export result.
In this guide
Create an editable flowchart from text with draw.io
Paste a small Mermaid example into free draw.io, edit a shape, then save an editable original and PNG. Includes screenshots and a file check.
In this guide
Fix JSON errors with JSONLint
Find a trailing comma, fix the JSON, and check what a valid result does and does not prove. Follow a small example with real screenshots.
In this guide
Compare two small CSV files by ID and check the changes
Compare two small CSV exports by ID with RowSlice. Use the practice files to check added, removed and changed rows, and spot blank or repeated IDs.