Valestiom

Converters

Convert measurements, images, files, and formats with local browser tools.

Browse converters

Choose a focused tool and get the result directly in your browser.

Photo conversions people actually need

Most image conversions trace back to one of three compatibility gaps. iPhones save photos as HEIC, which keeps quality high at a small size but is still refused by plenty of upload forms, print services, and older desktop software, so converting to JPG is the standard workaround.

WebP creates the same friction in the other direction: it is now served across much of the web, and the file you saved from a page may not open in the application you need it in. PNG to JPG is a size decision rather than a compatibility one, worth making when a photograph was saved as PNG and is several times larger than it needs to be, while JPG to PNG is the reverse move for when you need a lossless copy to edit.

Conversions that write JPG expose a quality control, because JPG discards detail to reach a smaller size. Around the default is usually indistinguishable from the original at normal viewing size; pushing it low enough to matter shows up first as blocky artifacts around sharp edges and text.

HEIC to JPG WebP to JPG PNG to JPG

Moving data between CSV, JSON, YAML, and TOML

Tabular and structured formats convert cleanly in one direction and awkwardly in the other. A JSON array of flat objects becomes CSV without loss, but nested objects have no natural column to occupy, so flatten the shape before converting rather than after. Going the other way, CSV carries no type information at all, which is why the converter preserves every cell as text and reports inconsistent row lengths instead of quietly guessing.

One detail worth knowing if the CSV is destined for a spreadsheet: a cell beginning with an equals sign, plus, minus, or at symbol is interpreted as a formula when the file is opened, which is a genuine injection vector when the data came from user input. The JSON to CSV converter protects those cells rather than leaving the problem to the recipient.

YAML and TOML are configuration formats rather than data interchange ones. Converting JSON to YAML is usually about making a config readable and diff-friendly; converting TOML to JSON is usually about feeding a config file to something that only speaks JSON. HTML tables convert in both directions too, including flattening merged cells that have no CSV equivalent.

CSV to JSON JSON to CSV JSON to YAML

Units, numerals, and measures

Unit conversion covers length, weight, temperature, area, volume, and speed in one place, which is the common case for recipes written in another country's measures, product dimensions quoted in inches, and travel speeds in the wrong system. Temperature is the one to watch, because it converts by offset as well as ratio and so behaves differently from every other unit in the list.

Roman numerals turn up in outline numbering, film credits, clock faces, and monument dates. Conversion here validates strictly in both directions and rejects non-canonical forms such as IIII or IC, which matters when you are transcribing an inscription and need to know whether what you read is actually well-formed.

Every conversion is arithmetic performed in the page. Nothing is submitted, so the numbers work offline and there is no round trip to wait for. Conversions that involve files rather than numbers sit with the image and PDF sets, and the full list is the quickest way to tell which one you need.

Convert units Roman numerals The full list of tools

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