Free file tools you can use instantly — no install needed
57 tools covering everything from merging PDFs, converting and compressing images, and converting iPhone HEIC, to extracting GIF/MP3 from video, removing backgrounds, and counting characters. Most tools run inside your browser using WebAssembly, so your files never leave your device.
Popular tools
- Merge PDFs Merge several PDF files into one, in whatever order you like. Free, no install or sign-up, and files are never uploaded to a server.
- PDF → JPG Convert every page of a PDF into a high-quality JPG or PNG image. Choose the resolution (DPI), and download multiple pages as a ZIP.
- JPG → PDF Combine several photos or scanned images into a single PDF. Choose paper size (A4, etc.), margins, and orientation.
- Compress PDFServer Shrinks file size by lowering the resolution of images inside the PDF and cleaning up redundant data. Use this to fit email attachment or upload size limits.
- Office → PDFServer Convert Word (docx, doc), Excel (xlsx, xls), PowerPoint (pptx, ppt), Hangul (HWP, HWPX), and ODT documents to PDF. Free, no program install needed.
- HWP → PDFServer Convert Hancom Hangul documents (HWP, HWPX) to PDF for free. Open or submit them as PDF right away, even on a PC, Mac, or phone without the Hangul program installed.
- PDF → WordServer Convert a PDF into an editable Word (DOCX) document, preserving text, table, and image layout as closely as possible. Free, no install or sign-up.
- Convert image format Convert JPG, PNG, WebP, AVIF, GIF, BMP, HEIC, or SVG images into the format you want, all at once. Supports batch conversion of multiple files.
- Shrink image size Shrinks JPG, PNG, and WebP photos with minimal quality loss. Supports a max width limit and batch compression.
- Resize image Change a photo's width/height in pixels or by percentage. Supports keeping the aspect ratio, batch-resizing multiple photos, and choosing the output format.
- HEIC → JPG Converts iPhone photos (HEIC, HEIF) into JPG or PNG that open anywhere — Windows, the web, you name it. Convert several at once, free, no install.
- Create ID photo Crop your photo to standard sizes — passport (3.5×4.5cm), resume (3×4cm), business card, or US visa (2×2 inch) — and lay it out on a 4×6 print sheet.
- Video → GIF Turn a section of an MP4, MOV, or WebM video into an animated GIF. Choose the size and frame rate, with palette optimization for sharper results.
- MP4 → MP3 Extracts just the audio from a video (MP4, MOV, MKV, WebM) and saves it as MP3, M4A, or WAV. Great for pulling audio from lecture recordings or your own videos.
- Shrink video size Reduces file size by adjusting the video's resolution and quality. Supports targeting a specific size (e.g. 25MB) and removing audio.
- Extract text from image (OCR) Extract Korean and English text from a photo, scan, or screenshot and copy it. Free, no install — images are never sent to a server.
- High-quality upscaling (AI)Server Sharpen and enlarge a small, blurry photo 2× or 4× with AI (Real-ESRGAN). Choose a model for photos or illustrations/comics, and compare side-by-side with the original.
- Remove backgroundServer AI automatically removes the background from a portrait or product photo, turning it into a transparent PNG. You can also replace it with any background color, like white.
- Speech-to-text (AI)Server AI (Whisper) transcribes speech from meeting recordings, lectures, interviews, and videos into text. Supports over 90 languages including Korean, and saves as TXT or SRT subtitles.
- Create favicon Create a complete website favicon set (favicon.ico, 16/32/180/192/512px PNG, site.webmanifest) and the HTML code, all at once, from an image, text, or emoji.
- Count characters Instantly count characters in a cover letter or report — with or without spaces, bytes, words, lines, paragraphs, and manuscript pages. Your text is saved automatically as you type.
- Korean/English keyboard conversion Turns "dkssudgktpdy" — typed in English without switching to Korean — into "안녕하세요," and also fixes English mistakenly typed in Hangul mode (based on the Dubeolsik layout).
- Fix garbled Korean in CSV Fixes the problem of Korean text breaking when you open a CSV in Excel. Automatically detects EUC-KR (CP949) or UTF-8 (BOM) and converts between them.
- Create QR code Create free QR codes for web addresses, Wi-Fi access, contacts, or text messages. Customize color and size, and save as PNG or SVG. Never expires.
- Ladder game Enter participants and outcomes (win/lose, penalties, who's buying coffee) to generate a random ladder, then reveal the results one by one or all at once.
- Spin the roulette Enter items to create a spinner wheel and spin it. Great for choosing lunch, drawing a winner, or picking a penalty. Each item's weight can be adjusted.
- Mosaic/blur Hide faces, license plates, ID numbers, or addresses in a photo with mosaic, blur, or solid fill. Select areas with a box or brush and save at the original resolution. Files are never uploaded to a server.
- Format/validate JSON Pretty-print JSON with indentation, minify it to one line, or sort its keys. Syntax errors tell you exactly which line and column the problem is on.
- Base64 encode/decode Encodes and decodes Base64 using UTF-8 so Korean text doesn't break. Also supports the URL-safe format, converting files to Base64/data URLs, and turning Base64 back into a file.
- Generate password Create random passwords of 8–64 characters by choosing from uppercase, lowercase, numbers, and symbols. Also supports excluding confusing characters, generating several at once, and showing strength (entropy). Everything is generated right in your browser.
- Test regex Enter a JavaScript regex to instantly highlight matches, and see group and named-group values plus the replacement result ($1, $<name>). Includes email and phone number examples.
- Convert timestamp Converts a Unix timestamp (seconds or milliseconds) to KST, UTC, or ISO 8601, and dates to timestamps. Automatically detects seconds vs. milliseconds by digit count.
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View all →Frequently asked questions
- Are all tools free? Do I need to sign up?
- Yes. All tools are free to use, with no installation or sign-up required. The site's running costs are covered by Google AdSense ads.
- Where is the file processed?
- Of the 57 tools, 50 run inside your browser, so your files never leave your device. Only the server-side tools (Compress PDF, Office → PDF, HWP → PDF, PDF → Word, High-quality upscaling (AI), Remove background, Speech-to-text (AI)) and the server compression option in Shrink video size send files to the server; the original and result files are deleted as soon as you receive the result, and files that are never downloaded are also deleted automatically after a set time.
- What tools are available?
- There are 57 tools across 8 categories (PDF tools, Image tools, Video/audio tools, Icon/favicon tools, Text tools, Data/QR tools, Developer tools, Draw/game tools). Type a tool name (e.g. merge pdf, heic) into the search box on the home page to find it right away.
- How many languages is it available in?
- It is available in 21 languages, including Korean. Tap the globe icon at the top of the screen to switch languages, or add a language code such as /en (English) or /ja (Japanese) to the start of the address.
- Who runs this site?
- OpenTools is run by OPENBLOG (www.openblog.com). To report a problem or get in touch, email [email protected].
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