Batch-rename file extensions (replace last extension or append) with collision checks; download renamed files individually or as one ZIP — all in your browser, no upload.
Category: File Conversion & Handling
Renaming runs in your browser — files are not uploaded. This only changes names in the ZIP/download; it does not transcode file contents.
Drop files here or click to browse (multiple)
Up to 150 files.
Files never leave your tab. You choose whether to replace only the final extension (foo.txt → foo.md) or append a suffix, preview the output filenames, resolve collisions if two rows map to the same name, then download a ZIP of renamed blobs or save files one by one.
Renaming an extension does not transcode content — a JPEG renamed to .png is still JPEG bytes. Use converters when you need a real format change.
No. All renaming and ZIP building runs in your browser.
Quick guidance for using our tools safely and effectively.
Files are processed on the server for conversion only and are not used for training or shared with third parties.
Use the formats suggested in each tool. Large media files may take longer — keep the tab open until processing finishes.
Browse related tools below or explore other categories from the main Dev Tools hub.
More utilities in the same category.
Export PDF pages as JPEG or PNG images in your browser (Mozilla pdf.js + canvas). Pick render scale, optional page list, and JPEG quality. Multi-page exports download as a ZIP. Max ~35 MB file size and up to 1000 pages (browser memory is the practical limit — use page ranges for huge jobs) — nothing is uploaded.
Stack JPEG or PNG files into one PDF with pdf-lib: reorder the list, choose A4 or Letter, set margins, and fit each image to the page — all client-side, no server upload. Up to 12 images per run.
Upload a PDF (up to 50 MB) and convert to a downloadable .docx via Dynamic Duniya’s file API — best for text-heavy PDFs; multi-column layouts and images may not transfer cleanly. Progress while uploading; open the result in Word or Google Docs and review formatting.
Upload Word .docx or legacy .doc (up to 50 MB) and download a PDF via the server file API. Output fidelity depends on LibreOffice on the server — review complex layouts. Progress while uploading; suggested download name converted.pdf.
Merge: first-page previews in a horizontal strip — drag cards to set merge order. Split: optional “Load page previews” then drag thumbnails (four per row, scrollable) to reorder pages before splitting by ranges or every N pages; ranges use preview slot numbers when previews are loaded. Zip when multiple parts. Client-side pdf.js + pdf-lib — max ~35 MB per file, 150 pages, 12 PDFs for merge.
Stamp text (font size, opacity, rotation, corner/center placement) or a JPEG/PNG image across every page using pdf-lib locally. Encrypted PDFs are not supported. Download a watermarked copy — your file never leaves the browser.
