LOCAL CALENDAR CONVERTER / ICS TO JSON

ICS to JSON

Extract common VEVENT properties into a stable JSON record array without expanding recurrences or changing time zones.

Processed in this browserOne UTF-8 .ics file up to 2 MB and 1,000 VEVENT records. Every event needs DTSTART; output is limited to eight common properties and 20 MB.

Step 1 / source

Choose the source

ICS - 1,000 events

Drop one file here

Choose the ics calendar events you want to turn into json event records.

Browse filesChecking publication status...

No file upload

This operation runs with browser APIs. Nirmion receives catalogue requests, not the selected source bytes.

Original stays unchanged

The converter creates a separately named output. It never writes back into the source file.

Bounded work

One UTF-8 .ics file up to 2 MB and 1,000 VEVENT records. Every event needs DTSTART; output is limited to eight common properties and 20 MB.

Plain-language method

How ICS to JSON works

Nirmion unfolds continued lines, validates complete VEVENT blocks, reads title, start, end, timezone, location, description, UID, and recurrence rule, decodes escaped text, and writes one source event per JSON object. It does not generate recurring instances.

01
Choose a valid source
Use a self-contained calendar export you are authorised to review. DTSTART is required; other supported fields are optional.
02
Review the conversion choices
ISO style improves readability without converting time zones. Source style keeps compact date text. Indentation changes whitespace only.
03
Inspect the separate result
The output ends in _nirmion_tools.json with eight stable property names. One recurring VEVENT remains one object with its RRULE text.

Useful when

Practical jobs this tool handles

Inspect event metadata in application code.
Create approved calendar fixtures.
Review a calendar export without account access.

Before converting

Check the source and destination rules

Confirm event count and ownership.
Review timezone beside local date-times.
Do not treat one recurring object as one occurrence.

Know the boundary

Know what the destination format cannot keep

Attendees, alarms, exclusions, overrides, attachments, and provider-specific extensions are outside this common-property projection. Keep the original ICS for full calendar behavior.

Quick answers

Questions before you convert

The conversion contract is deliberately explicit.

Are recurring events expanded?

No. RRULE remains text on the source event object.

Are time zones converted?

No. TZID is reported separately and UTC values retain Z.

Are formula-like titles changed?

No. JSON does not execute spreadsheet formulas, so source event text remains unchanged.