Drop a file here
About Highlight PDF — Free Online Tool
Highlight PDF lays translucent coloured blocks over areas of a page, so the words underneath stay readable through them.
Each highlight is a filled rectangle drawn into the page content at roughly a third opacity, which is what keeps the text legible rather than covered. Two things follow. It marks an area, not a phrase: you give coordinates — a width and height, or a list of boxes as JSON — because nothing here searches for words to wrap a box around. And the mark is page content rather than a /Highlight annotation, so it travels with the file and prints with it, but no reader will offer to lift it off later.
Marks are applied in the browser, so a contract you are reading through for yourself is not shared with anyone by using this.
Flagging the clauses that need a second look before a meeting, marking the figures a reviewer should check, picking out passages in study material, and pointing a colleague at the right paragraph of a long policy.
Also known as: highlight text in pdf · mark pdf text · yellow highlighter pdf
When to use it
Flags the clauses that need a second look, or the figures a reviewer should check, in a way that prints with the file.
How it works
Paints each box as a filled rectangle at about a third opacity, so the text underneath shows through rather than being covered.
It Marks an Area, Not a Phrase
Nothing here searches for words to wrap a box around. You supply coordinates — a position with a width and height, or a list of boxes as JSON — measured from the corner you nominate.
How to Use Highlight PDF in 4 Easy Steps
Follow this simple guide to process your files in seconds directly inside your browser tab.
Select or Drop Your PDF
Drag and drop your PDF directly into the Highlight PDF workspace above or click 'Choose files'. You can process up to 1 file in a single run.
Configure Your Preferences
Adjust the available optimization sliders, target formats, or custom options. Flags the clauses that need a second look, or the figures a reviewer should check, in a way that prints with the file.
Instant In-Browser Execution
The client-side engine executes Highlight PDF locally on your device hardware with zero server latency and 100% private in-memory sandboxing.
Preview & Download PDF
Inspect the processed file, compare file size savings or output quality, and click Download to save the finished PDF file directly to your disk.
Why Use Highlight PDF on ShortTrick
Engineered for maximum speed, strict privacy, and frictionless digital productivity.
100% Private & Local
Files processed with Highlight PDF never leave your computer or phone. Zero cloud uploads, zero tracking, and zero risk.
Blazing Fast Engine
Powered by compiled WebAssembly code running directly in your browser with sub-second execution for Highlight PDF.
No Paywall or Account Required
Highlight PDF is completely free with no hidden charges, watermarks, email signups, or artificial daily limits.
High-Fidelity Quality
Advanced algorithms preserve crisp vector text, clear colors, and structural layout integrity.
Generous 50 MB Size Limit
Handle files up to 50 MB and process up to 1 files in convenient batches with Highlight PDF.
Cross-Device Compatibility
Runs seamlessly in modern browsers on Windows, macOS, Linux, iOS (iPhone/iPad), and Android.
Supported Formats & Limits
Designed for high performance with browser-side memory guarantees.
50 MB
1
Frequently Asked Questions About Highlight PDF
Common questions regarding Highlight PDF, data privacy, file format compatibility, and usage limits.
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