Free, no sign-up, 100% local
Free online tools that get straight to the point
Image converter, video and photo editors, QR codes, hashing, calculators: free tools with no sign-up that run entirely in your browser.
Private by design
Calculations and files are processed in your browser. Nothing is sent to a server.
Free and instant
No sign-up, nothing to install. Results appear as you type or as soon as you drop a file.
Works everywhere
On Windows, macOS, Linux and ChromeOS, in any modern browser, with no plug-in.
Kortex sites
93 tools grouped by theme, each on its own site.
Calculator
Percentages and everyday calculations: clear, free calculators that work right in your browser, with no sign-up.
Converter
Convert HEIC, JPG, PNG, WebP, AVIF, SVG and ICO images for free. The conversion runs in your browser: your files never leave your device.
HEIC to JPG
Convert your iPhone HEIC photos to JPG, readable everywhere. Free, no sign-up, no upload: the conversion runs in your browser.HEIC to PNG
Convert your iPhone HEIC photos to lossless PNG. Free, no sign-up, no upload: your photos never leave your device.HEIC to WebP
Convert HEIC photos to WebP for the web: small files readable by every browser. Free, no upload, done in your browser.WebP to JPG
Convert WebP images to JPG to open, print or share them anywhere. Free, no sign-up, no upload: done in your browser.WebP to PNG
Convert WebP images to PNG and keep transparency. Free, no sign-up, no upload: the conversion runs in your browser.PNG to JPG
Convert PNG images to JPG and make them much smaller. Free, no sign-up, no upload: the conversion runs in your browser.JPG to PNG
Convert JPG images to PNG with no further quality loss. Free, no sign-up, no upload: done entirely in your browser.JPG to WebP
Convert JPG photos to WebP for a faster website: same look, much smaller files. Free, no upload, done in your browser.PNG to WebP
Convert PNG images to WebP and keep transparency, with much smaller files. Free, no sign-up, no upload.JPG to AVIF
Convert JPG photos to AVIF, often half the size at equal quality. Free, no sign-up, no upload: done in your browser.PNG to AVIF
Convert PNG images to AVIF for much smaller files, transparency included. Free, no sign-up, no upload.WebP to AVIF
Convert WebP images to AVIF to shrink them even further at comparable quality. Free, no sign-up, no upload.AVIF to JPG
Convert AVIF images to JPG to open them in any program, website or printer. Free, no sign-up, no upload.AVIF to PNG
Convert AVIF images to PNG and keep transparency, to edit them in any software. Free, no sign-up, no upload.AVIF to WebP
Convert AVIF images to WebP for better compatibility while keeping files small. Free, no sign-up, no upload.SVG to PNG
Convert SVG logos and icons to sharp PNG images at the exact width you need, transparency kept. Free, no upload.SVG to JPG
Convert SVG drawings to JPG images at the width of your choice. Free, no sign-up, no upload: done in your browser.PNG to ICO
Create a multi-size ICO icon from a PNG: website favicon or Windows shortcut icon. Free, no sign-up, no upload.JPG to ICO
Turn a JPG photo or image into a multi-size ICO icon for a favicon or Windows shortcut. Free, no upload.ICO to PNG
Extract the image of a favicon or Windows icon as PNG, in the best resolution available. Free, no upload.
Video
Video editor and automatic subtitles, free and with no sign-up: edit, transcribe and export to MP4. Your videos never leave your device.
Video editor
Edit your videos online: trim, merge, add text, music and transitions, export to MP4. Free, no sign-up, nothing is uploaded.Trim a video
Trim the start or end of a video online, frame-accurate, and download it as MP4. Free, no sign-up: the video stays on your device.Split into parts
Split a video into several parts and download each part as MP4. Free, no sign-up, no upload: everything happens in your browser.Merge videos
Combine several videos and photos into a single MP4 video, with crossfades if you like. Free, with no sign-up or upload.Add music
Add music or a voice-over to your video (MP3, WAV, M4A), set the volume and fades, export to MP4. Free, no file upload.Add text
Add a title or captions to a video: font, size, color, background, animation, position with the mouse. Free, no sign-up.Video speed
Speed up (1.5x, 2x) or slow down (0.5x) a video online without changing the pitch of the voice, and download it as MP4. Free.TikTok format (9:16)
Turn a landscape video into the vertical 9:16 format for TikTok, Instagram Reels and YouTube Shorts, with a blurred background or crop. Free.Square format (1:1)
Make a video square (1:1) for Instagram or Facebook, with a blurred background or crop, and export to MP4. Free, no upload.Mute a video
Remove the sound from a video online and download it as a silent MP4, or replace it with music. Free, no sign-up, no upload.Automatic subtitles
Generate your video’s subtitles automatically, correct them and export as SRT or MP4. Private transcription: nothing is uploaded.Add subtitles
Add subtitles to your video: automatic transcription, correction, then SRT or a subtitled MP4 video. Nothing is uploaded to a server.Transcribe a video
Transcribe a video to text for free, with or without timestamps. Transcription happens in your browser: your video stays private.Transcribe audio
Transcribe an audio file (MP3, WAV, M4A) to text, free and with no sign-up. Nothing is uploaded: transcription happens on your device.Generate an SRT
Create your video’s SRT file automatically: transcription in the browser, synchronized and editable subtitles. Free and private.Burn in subtitles
Burn subtitles into your MP4 video: automatic transcription or an existing SRT file, adjustable style. Everything happens in your browser.TikTok captions
Add TikTok, Reels and Shorts-style captions: large text, spoken word highlighted, 9:16 format. Private transcription, nothing is uploaded.SRT to VTT
Convert an SRT subtitle file to WebVTT (.vtt) instantly, without uploading it to a server. Timings and text are kept.VTT to SRT
Convert a WebVTT (.vtt) subtitle file to SRT instantly, without uploading it to a server. Timings and text are kept.Edit an SRT
Edit an SRT or VTT file online: text, timings, split, merge, find and replace. Free, and the file stays on your device.Shift subtitles
Shift all the subtitles of an SRT or VTT file earlier or later to resync them with the video. Free, nothing is uploaded.
Kortex QR Code
Create, customize and scan QR codes for free: static, with no sign-up, no tracking and no expiry date. Everything happens in your browser.
QR code generator
Create a free QR code with no sign-up and no expiration: link, Wi-Fi, contact, payment… Customizable, checked, in SVG, PNG or PDF.Wi-Fi QR code
Create a free Wi-Fi QR code: your guests connect without typing the password. WPA2, WPA3, hidden network. Nothing is uploaded.Business card (vCard)
Create the vCard QR code for your business card: name, phone, email and address are saved to contacts in one scan. Free.QR code with logo
Add your logo to the center of a free QR code: error correction raised, size checked and code read back to make sure it scans.Bulk QR codes
Generate hundreds of QR codes from a CSV file or a list: ZIP of SVG or PNG files, PDF label sheet. Free, and your data is never uploaded.QR code scanner
Scan a QR code with your computer or phone camera, no app needed. Links are checked before opening, and nothing is uploaded.QR code for a link
Turn a link into a free QR code: website, form, menu, social media page. Static code, with no redirect or tracking.Custom QR code
Customize your QR code: colors, gradient, rounded or dot modules, corner finder patterns, “Scan me” frame. Contrast check included.No expiration
Create a QR code that never expires: static, free, with no sign-up or subscription. It will work as long as your page exists.Static or dynamic
Static or dynamic QR code: which should you choose? Why dynamic codes stop working and how to create a code that never expires.Email QR code
Create a QR code that opens a prefilled email: recipient, subject and message. Ideal for customer support or sign-ups. Free.SMS QR code
Create a QR code that prepares a text message: number and message prefilled, for a contest, a confirmation or an opt-out. Free.WhatsApp QR code
Create a QR code that opens a WhatsApp chat with your number and a prefilled message. Official wa.me link, free and with no sign-up.Phone QR code
Create a QR code that dials a phone number: one scan and the call is ready. For shop windows, vehicles and ads. Free.SEPA transfer QR code
Create a SEPA transfer QR code (EPC standard, GiroCode): beneficiary, checked IBAN, amount and reference prefilled in the banking app.Event QR code
Create a QR code that adds an event to the calendar: title, date, time, location. For posters, invitations and announcements. Free.Location QR code
Create a QR code that opens a GPS location in the phone’s map app: a site entrance, a meeting point. Free, with no sign-up.Print size
What size should a printed QR code be? Calculate the minimum size from the scan distance and the code density, in cm and pixels.Label sheet
Create an A4 sheet of QR code labels from a list: columns, rows, margins and text under each code are adjustable. Print-ready PDF, free.QR code from an image
Read the QR code in a photo, a screenshot or a pasted image, without a phone. Analyzed in your browser: the image is never uploaded.Check a QR code
A QR code can hide a fraudulent link. Scan it here: real domain, shortened link, misleading characters and traps flagged before opening.
Kortex Photo
Edit your images with layers, text, shapes and filters. Free photo editor with no sign-up: your images never leave your device.
Photo editor
Edit photos online: layers, selections, brush, text and filters. Export to PNG, JPG or WebP, with no account and entirely on your device.Crop
Crop a photo with a free, square, portrait or landscape ratio. Adjust the frame and export your image without uploading it to a server.Resize
Change an image’s size in pixels, keeping or changing its aspect ratio. Export to PNG, JPG or WebP right in your browser.Compress
Reduce an image’s file size by adjusting its quality and dimensions. See the real file size before downloading as JPG or WebP.Add text
Add editable text to a photo. Choose the font, color, size and alignment, then export your creation.Blur
Apply an adjustable Gaussian blur to an image layer. Change the radius at any time and export the result locally.Brightness
Brighten or darken a photo with a non-destructive adjustment. Fine-tune the exposure too, and export without uploading your files.Contrast
Increase or soften a photo’s contrast. Editable per layer, with a local preview and export to PNG, JPG or WebP.Black and white
Turn a photo black and white with a non-destructive adjustment. Fine-tune contrast and brightness before downloading your image.Rotate
Rotate an image by 90 degrees or choose a precise angle. Transform layers and export your composition in the browser.Flip
Mirror an image with horizontal and vertical flips. Per-layer settings, entirely local.Transparency
Delete a selected area to make an image transparent. Use selections, the eraser and PNG or WebP export.Square photo
Make a square photo with an adjustable 1:1 frame. Move the frame and export at the size you want.Portrait 4:5
Set up a 4:5 portrait crop and export your image at 1080 × 1350 pixels. Your files are processed only in your browser.Story 9:16
Prepare a vertical 9:16 image for a story. Crop, add text and export your visual at 1080 × 1920 pixels.
Kortex Hash
Hash generator (MD5, SHA-256, bcrypt…), HMAC, identifier, integrity checker and recovery by dictionary or brute force. Everything runs in your browser.
Hash generator
Compute the MD5, SHA-1, SHA-256, SHA-512, SHA-3, BLAKE2/3… hash of a text or file. Salt, hex or Base64. Everything is local, nothing is uploaded.MD5 generator
Compute the MD5 hash (128 bits) of a text or file in your browser. Useful as a checksum; MD5 is broken for security purposes.SHA-256 generator
Compute the SHA-256 hash (256 bits) of a text or file in your browser. The robust standard for checking integrity. Nothing is uploaded.SHA-512 generator
Compute the SHA-512 hash (512 bits) of a text or file in your browser. The 512-bit variant of SHA-2. Everything is local, nothing is uploaded.HMAC
Compute an HMAC (keyed hash, RFC 2104): HMAC-SHA256, SHA-512, SHA-1, MD5… Message and key as text or hex. Everything is local.Hash identifier
Paste a hash: identify the possible algorithms from its length and pattern (MD5, SHA-256, bcrypt, Argon2…). 100% local analysis.Hash comparison
Compare two hashes at a glance (case and separators ignored), in constant time, with identification of the likely algorithm. Local.bcrypt generator
Generate a bcrypt hash for your passwords, with adjustable cost and automatic salt. Verifier included. 100% local, nothing is uploaded.Argon2 generator
Generate an Argon2id hash (adjustable memory, passes and parallelism) for your passwords. Verifier included. Everything is local.scrypt generator
Generate a memory-hard scrypt hash (adjustable N, r, p) for your passwords. Verifier included. Everything is local.PBKDF2 generator
Generate a PBKDF2-HMAC-SHA256 hash (adjustable iterations) for your passwords. Verifier included. 100% local, nothing is uploaded.File integrity checker
Drop a file, paste its reference hash (SHA-256, MD5…): the tool confirms whether the file is intact. Algorithm detected, 100% local.Checksum file
Generate a SHA256SUMS file for several files, or check files against a reference list. Compatible with sha256sum. Everything is local.Dictionary recovery
Test a word list (yours or the one provided) against MD5, SHA-1, SHA-256… hashes, with simple rules. Multi-threaded, 100% local.Brute-force recovery
Test every combination of a character set against an MD5/SHA-1/SHA-256 hash, with time estimation and GPU acceleration. 100% local.