# Diagram studio > Browser-only file conversion. Selected files are processed on this device and are not uploaded to a conversion server. Source: https://localconverter.tech/diagram-studio Turn Mermaid text into flowcharts, sequence, ER, class, mindmap and Gantt diagrams. Choose Mermaid flowchart, sequenceDiagram, erDiagram, classDiagram, mindmap or gantt syntax. These are text descriptions, not natural-language prompts. Paste UTF-8 text into the main input or upload a matching file. A selected file takes priority over the pasted text. ## Useful tasks - Render a Mermaid flowchart or sequence diagram. - Export a supported diagram as SVG or PNG. - Inspect a technical diagram defined in text before sharing it. ## Steps 1. **Provide the source**: Paste UTF-8 text into the main input or upload a matching file. A selected file takes priority over the pasted text. Read the operation note before starting, because supported syntax and file limits are part of the result contract. The original file is not overwritten or renamed by this workflow. 2. **Choose the intended result**: Review the controls for Download format, Diagram theme. Change settings according to the file or text you actually supplied. Defaults are a starting point rather than a promise that every source uses the same conventions. Choose Mermaid flowchart, sequenceDiagram, erDiagram, classDiagram, mindmap or gantt syntax. These are text descriptions, not natural-language prompts. 3. **Create and inspect the output**: Use the main action button to run diagram studio. Local processing checks the source and reports malformed or unsupported inputs. A completed job appears in Your results, with a download action and a preview when the output supports it. If the operation fails, read its message and correct the source or settings before retrying; changing only a filename does not change file contents. 4. **Save and verify the result**: Download the finished output and open it in the application or workflow that will consume it. Choose the original source, adjust the settings, create the result and inspect the saved output. Check the values, layout, encoding or parsed structure relevant to your task. Keep the source when you may need another set of settings later. Temporary job downloads are session-owned and expire; saving your own copy is the way to retain a result. ## Settings - **Download format**: Choose download format according to the result you need. Available choices: svg; png. The initial selection is svg. - **Diagram theme**: Choose diagram theme according to the result you need. Available choices: default; dark; neutral; forest. The initial selection is default. ## Try diagram studio with a small source Try this source: flowchart LR A[Choose a file] --> B[Convert locally] B --> C[Download result]. Use the initial settings, inspect the result and then change one setting to understand its effect. Choose Mermaid flowchart, sequenceDiagram, erDiagram, classDiagram, mindmap or gantt syntax. These are text descriptions, not natural-language prompts. ## Check the result Choose the original source, adjust the settings, create the result and inspect the saved output. Mermaid diagrams only, up to 30,000 characters. External images, links, HTML labels and initialization directives are disabled. Rendering has a 20-second deadline. Open the saved output in the app or workflow where you plan to use it. Check one representative result before repeating the same settings with more files. The original files stay unchanged. ## Limits - Files are processed on this device. Browser memory and engine-specific limits apply. Save results before reloading. - Mermaid diagrams only, up to 30,000 characters. External images, links, HTML labels and initialization directives are disabled. Rendering has a 20-second deadline. - Upload one file with a combined size of at most 100 MB. The completed output must fit within 200 MB. - Pasted text and uploaded text have operation-specific UTF-8 byte limits. Productivity tools accept up to 1 MiB (1,048,576 bytes); non-ASCII characters can use several bytes each. If a file is selected, it takes priority over pasted text. - Selections and completed jobs stay available while you navigate inside this tab. Use My files to revisit results. Reloading or closing the tab clears the workspace; download results you want to keep first. ## Questions ### What does Diagram studio produce? Turn Mermaid text into flowcharts, sequence, ER, class, mindmap and Gantt diagrams. Choose Mermaid flowchart, sequenceDiagram, erDiagram, classDiagram, mindmap or gantt syntax. These are text descriptions, not natural-language prompts. ### Which source should I use? Paste UTF-8 text into the main input or upload a matching file. A selected file takes priority over the pasted text. Supported file extensions are txt, md, mmd. The processing engine checks actual contents; a matching extension alone does not make malformed content valid. ### Why did this input fail? Mermaid diagrams only, up to 30,000 characters. External images, links, HTML labels and initialization directives are disabled. Rendering has a 20-second deadline. Check syntax, required inputs and the ranges shown next to settings. An error keeps unsupported data from being presented as a successful conversion. Correct the source and retry rather than repeatedly resubmitting an unchanged invalid input. ### How should I check the download? Choose the original source, adjust the settings, create the result and inspect the saved output. Review the saved content in its destination application, including a typical case and any boundary values important to your use. A completed operation confirms processing finished; it cannot determine whether the supplied settings match your wider business requirements. ### Does Diagram studio upload files to another service? Processing runs in this browser, on your device. Files and pasted input are not uploaded to a conversion server. The website and required engine assets must load first; large operations depend on available device memory. ### Can I continue after changing pages? Selections and completed jobs stay available while you navigate inside this tab. Use My files to revisit results. Reloading or closing the tab clears the workspace; download results you want to keep first. ## Related guides - [Markdown live editor](https://localconverter.tech/markdown-editor.md) - [HTML / CSS / JavaScript formatter](https://localconverter.tech/format-code.md) - [DOCX preview & extraction](https://localconverter.tech/docx-preview.md)