KIOHWKIO HARDWARE TEST
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    Tools
      Hardware tests39
      Input devicesKeyboard testMouse testGamepad testStylus and pen testPS5, PS4 and Switch controller testDouble click testScroll wheel test
      DisplayMonitor testRefresh rate testStuck pixel fixerColor blindness testScreen size and PPI calculatorMonitor calibration test
      Audio and cameraSpeaker testMicrophone testWebcam testHearing test3D audio testAudio latency testDecibel meterFocus sounds
      MobileTouch screen testSensor testVibration testGPS testNFC test
      NetworkMy IP addressPing and jitter testDNS speed testWebRTC leak testIPv6 test
      Speed and reflexesCPS testReaction time testTyping speed test
      SystemSystem infoCPU and GPU benchmarkStorage speed testUSB device info
      MusicMIDI keyboard test
      PDF tools41
      Organize PDFMerge PDFSplit PDFRemove pagesExtract pagesOrganize PDFScan to PDFAdd pages to PDFMultiple pages per sheet
      Optimize PDFCompress PDFRepair PDFOCR PDFPDF to PDF/A
      Convert to PDFJPG to PDFOffice to PDF
      Convert from PDFPDF to JPGPDF to WordPDF to PowerPointPDF to MarkdownPDF to ExcelExtract images from PDFPDF to textPDF to CSVPDF to HTML
      Edit PDFRotate PDFAdd page numbersAdd watermarkCrop PDFFill PDF formsEdit PDFEdit PDF metadataChange PDF page sizePDF bookmarksBates numberingAdd QR code to PDFCreate fillable PDFAttach files to PDF
      PDF securityUnlock PDFProtect PDFSign PDFRedact PDFCompare PDF
      AI PDF toolsSummarize PDF (AI)Coming soonTranslate PDF (AI)Coming soonChat with PDF (AI)Coming soon
      Media tools25
      ImagesHEIC to JPGCompress imageResize imageImage converterEXIF viewer and removerRemove backgroundQR code generatorQR code scannerCrop and rotate imageWatermark imagesImage to text (OCR)
      Audio and videoVideo to MP3Compress videoTrim videoScreen recorderWebcam recorderVoice recorderVideo to GIFVideo converterRotate and crop videoMerge videosAudio cutterAudio converterNormalize audio
      FilesFile hash checker

      Protect PDF

      Runs locally

      Set a password; the PDF will ask for it every time it is opened.

      How to use

      1. Choose or drop a PDF.
      2. Enter a password twice and choose the permissions.
      3. Press Protect PDF.

      Frequently asked questions

      How secure is it?

      It uses AES-256 encryption, the strongest standard for PDF files. A long password matters most.

      I forgot the password.

      It cannot be recovered. Keep the unprotected original somewhere safe.