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Cold email variable previewer
Preview literal {{key}} replacements from a JSON object and see which values remain unresolved.
Prepare your inputs
Paste a template and a small JSON object containing scalar values. The preview treats input as text, so neither HTML nor embedded JavaScript executes. It does not access your contact database.
Runs in this browser. Inputs are not sent by this tool or saved in browser storage. Start with the fictional example; use redacted text for reviews.
How it works
Keys are matched literally and case-sensitively. Missing, null or empty values leave the original token visible. Nested paths, expressions and provider-specific fallback syntax are outside this utility.
Worked example
Hi {{first_name}}, with {"first_name":"Alex"} becomes Hi Alex,. If company is absent, {{company}} remains visible for review instead of silently becoming a plausible blank.
Limits and interpretation
The syntax is an illustrative preview and may differ from a campaign editor. Always test the actual deployed sender with a controlled contact before launch.
Examples are synthetic, not customer results. Zintara practical guide library