ABOUT
About Redline PDF.
Redline PDF is software for reviewing PDF construction drawings. Calibrate a sheet, mark it up, measure it, and send a clear result, all in your browser.
What it does
Open a PDF drawing, calibrate the sheet against a dimension you trust, and review it with clouds, callouts, text, stamps, measurements and counts, and with walls, doors and windows that carry their sizes. Redline also reads the annotations already in a PDF someone sends you. With Pro, export a PDF with editable annotations, a clean PDF or a CSV of quantities; Free exports a flattened PDF.
Who it is for
The architect, engineer or reviewer who checks drawings on their own. Established drawing review software is mostly sold to firms, per seat, as desktop programs. Redline is one plan for one person, in a web browser, on Windows, a Mac or an iPad.
How your drawings are kept
A drawing you save belongs to your account and is encrypted on the server. No other account can open it, and you can download your drawings at any time, during the trial and after it. Subscriptions are sold through Paddle, the merchant of record, so card details go to Paddle, never to Redline. The privacy policy has the detail.
How it is priced
Every account starts with seven days of Pro, with no card. After that you keep Redline Free for as long as you like, or choose Pro at $15 a month or $150 a year. Compare the plans.
How it changes
Redline is updated often, and every update is written up. The latest shipped on 16 September 2026. See what’s new.
About the name
This Redline is software for PDF drawings, and redlinepdf.net is its home. Businesses elsewhere that trade as Redline Services, in fields such as heating, IT and telecoms, are separate companies.
Talk to us
Email support@redline-services.net and a person answers. In the app, Help sends a problem report or a rating straight to us.
Try it on the sample drawing
Redline runs in the browser — nothing to install. Open the demo to try tools on a sample drawing. Demo edits are temporary; your own files, saving, signatures, exporting, printing and downloads come with the seven-day trial, which takes no card. After it you keep Redline Free, or choose Pro at $15 a month or $150 a year. Compare the plans.
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