ConvertAll

Every conversion runs on your device

Choosing the right target format

Conversion is mostly about knowing where a file is going. For images on the web, WebP or AVIF give the smallest files at comparable quality, while PNG stays the choice for screenshots and anything needing lossless edges; JPG remains the safe bet for photographs headed to older systems. For data, CSV is what spreadsheets and import tools eat, JSON is what APIs and code expect, and XLSX preserves multiple sheets and types — converting between them here is how you bridge a data export to wherever it needs to land. Watch the classic pitfalls the converter surfaces: Excel coercing long numbers and dates during CSV round-trips, UTF-8 text losing accents when a legacy tool assumed the wrong encoding, and nested JSON flattening lossily into rows. For documents, PDF freezes layout for sharing while DOCX and Markdown stay editable — convert to PDF last, not first.

Some jobs deserve a dedicated workspace instead of a mini-tool: QR Studio for styled, print-ready QR codes, Color Studio for contrast checking and palettes, CodeFormat for beautifying source code, and JSON Studio for exploring and querying payloads before you convert them.

Step-by-step: converting a batch of files

Drop one or more files onto the dashed zone, or click it to open the file picker; multiple selection is allowed and every file lands in the Uploaded files list with a count badge. The Convert from selector detects the source type from the extension and MIME type, and Convert to is populated with the targets available for that category — images offer PNG, JPG, WebP, GIF, BMP, TIFF, ICO, SVG and AVIF, audio offers MP3, WAV, OGG, FLAC, AAC, M4A and Opus, and so on across the nine categories shown in the tabs under the converter. Choosing JPG or WebP reveals a Compression Quality slider (10–100 %, default 80 %); choosing a lossy audio target reveals an Audio Bitrate menu with 128, 192 and 320 kbps. The swap button between the two selectors reverses the direction when you need to go back the other way.

Press Convert now and the progress block shows a percentage, an estimated time remaining and the current file; conversions run one after another so memory stays bounded. When the queue finishes, each result appears with its new size and a download link, and Download all as ZIP packages the whole set in one archive built in the browser. Convert another file clears the queue while leaving the category tabs as they were. The category tabs themselves double as documentation — click one to see which library performs the work and which edge cases to expect for that family of formats.

Real-world use cases

• Preparing images for a website. Drop a folder of PNG screenshots, choose WebP at 80 % quality, and download the ZIP. Files typically shrink by 60–80 % with no visible difference, and the originals never leave your laptop.
• Cleaning up a data export. A CRM export arrives as XLSX but the import tool wants CSV — convert here, then open the result in a text editor to confirm the delimiter and that phone numbers kept their leading zeros.
• Making a favicon set. Convert a 512 px PNG logo to ICO; the builder embeds the standard sizes in one container so the same file works in old and new browsers.
• Sharing a short clip as a GIF. Trim a screen recording to a few seconds first, then convert MP4 to GIF. GIF is limited to 256 colours per frame and grows quickly, so short, small-resolution clips give the best results.
• Reading a web font's source. Convert WOFF2 to TTF to inspect or edit glyphs in a desktop font editor, then convert back to WOFF2 for deployment.

Common mistakes and how to avoid them

Converting a transparent PNG to JPG fills the transparent area with a flat colour because JPG has no alpha channel — use WebP or AVIF when you need both transparency and small size. Going from SVG to PNG rasterises the drawing at a fixed size, so zooming the result later looks blurry; keep the SVG for layouts and export PNG only at the exact dimensions required. On the data side, opening a converted CSV in Excel and saving it again can silently reformat dates, strip leading zeros and change the text encoding; if the file is destined for another program, inspect it in a plain editor instead. Audio re-encoded from MP3 to MP3 at a higher bitrate does not gain quality — lossy compression loses information permanently, so convert from the original WAV or FLAC when you have it. Finally, very large videos and multi-hundred-megabyte archives are bounded by your browser's memory: if a conversion fails near the end, close other tabs or split the job into smaller files rather than retrying the same batch.

Further reading

Unsure which image format to pick? WebP vs AVIF vs PNG vs JPG compares size, quality and browser support. Before moving spreadsheets between tools, read CSV, JSON and XLSX conversion pitfalls. Browse all guides for more.

Frequently asked questions