About Ratio

Ratio is a free web tool for people who put video on screens: projection, LED walls, broadcast and events. It makes pixelmap test cards for any resolution and does the screen maths around them. It runs entirely in your browser, with no ads and no tracking. Open Ratio.

What it does

• Pixelmap test cards for any resolution: a labelled grid, circles, colour bars, colour ramps, safe areas and an edge border. Choose the colours, patterns and elements, then download a PNG, JPEG or WebP.
• LED walls: enter the panel size in pixels and the number of panels, and the card draws every panel border and number. Or start from the wall's size in metres or feet and a cabinet type with the LED wall resolution calculator.
• Video test loops: a seamless MP4 loop with moving patterns, so frozen playback is easy to spot. Optional sync markers add timecode, a white flash on every second and a matching 1 kHz beep for checking sync between screens and sound.
• Several screens at once: keep a list of screens, each with its own card settings, and download every card in one zip. Print a one-page summary sheet or export a CSV.
• Output raster: place screens on one media server output (such as 3840 × 2160, or any custom size), drag them into position and export the combined pixelmap plus a CSV of positions.
• Tech spec reader: drop in a venue's PDF, Word, Excel or CSV document and Ratio lists the screen sizes it finds. The file is read in your browser and never uploaded.
• Aspect ratio maths: reduce a size to its ratio, find the same ratio at another width or height, compare four rounding methods, fit one frame into another (letterbox or crop) and get print sizes at any DPI. The method page shows the arithmetic.
• ffmpeg command builder: a ready-to-paste command to scale or convert footage to the current size, with H.264, H.265, ProRes and HAP.
• Share link: send a whole screen list as one link, no account needed.

Questions

Is Ratio free?

Yes. Every tool on this page is free, with no watermark and no sign-up. An optional account only keeps your projects in sync across devices.

Are my files uploaded?

No. All maths, card drawing, video recording and tech spec reading happen in your browser. Projects leave your computer only if you sign in and save them.

What is a pixelmap?

A test image made at a screen's exact resolution. Played on the real screen, it shows straight away whether the picture is scaled, cropped, stretched or offset, and on an LED wall which panel is where.

Which media servers and players does it work with?

Any of them. The cards are plain image files and the loops are MP4, so they play in Resolume, disguise, TouchDesigner, Millumin, Watchout, QLab, a laptop or a TV.

How do I make a 1920 × 1080 test card?

Open Ratio at 1920 × 1080, adjust the card in section 2 and press Download. Any other size works the same way: type it in section 1.

Who makes Ratio?

Drawing Circles. Questions, ideas and wrong results go to [email protected].