Hindsight

About

Hindsight is the DevTools you forgot to open.

It runs quietly in the background and records every network request, console error, user action, and screenshot. When something breaks, you scrub back through time and ship a faithful bug report without re-running anything.

WHY IT EXISTS

You hit a bug. You jump to DevTools. You refresh. The error doesn't happen again. The XHR you needed has scrolled out of the panel. You couldn't open DevTools fast enough.

Hindsight is always on. By the time you realise something interesting happened, the evidence is already captured.

WHAT IT CAPTURES

• Network: fetch, XMLHttpRequest, WebSocket, SSE — full request and response with headers and bodies
• Console: error, warn, info, plus unhandled rejections and uncaught errors with stack traces
• User actions: clicks, form inputs (passwords always masked), SPA route changes
• Screenshots on error: a single JPEG at the moment of the failed request
• Performance signals: long tasks over 100 ms, cumulative layout shift, white-screen heuristic
• Recording mode: explicit Record / Stop adds cursor trail, scroll, and 2-second screenshots

THE KILLER FEATURE — SHARE WITHOUT SETUP

One click saves the entire session as a single self-contained HTML file. Your teammate drags it into any browser tab and sees the whole story — scrubber, narrative, request/response panels — with no extension, no service, no login. Works offline.

The same payload also flows into Slack, Discord, Microsoft Teams webhooks, GitHub Issues, mailto drafts, JSON downloads, HAR exports, cURL commands, and ZIP archives. Size-aware formatters truncate gracefully when the destination has paste limits.

PRIVACY-FIRST BY DESIGN

• Zero outbound network requests except ones you explicitly initiate
• No telemetry. No analytics. No tracking pixels. No third-party SDKs
• Sensitive headers (Authorization, Cookie, X-API-Key, X-Auth-Token, Proxy-Authorization, Set-Cookie) are masked at capture time, before being written to local storage — the original values are never persisted, so they cannot leak through a future bug or compromised machine
• Built-in body pattern masking for credit cards (Luhn-validated) and Turkish national IDs (TCKN with checksum)
• Form-field masking for password inputs and credit-card autocomplete
• Custom regex patterns you define in Settings → Privacy
• Disable individual rules per future capture when you genuinely need raw values for your own debugging

A privacy preview modal shows the exact event count, redaction summary, and destination identity before every send.

KEYBOARD-FIRST INSPECTION

• Side panel scrubber with a dual-handle range filter — clip both edges of the timeline
• Filter chips: Failed / API only / All
• Live full-text search across event type, URL, and body
• Host picker to focus on a single origin
• Cluster banners group repeated failures into one summary row
• "Replay this request" button re-fires a captured request from the extension context

ZERO SETUP

Install, pin the icon, browse normally. Defaults work the moment you load. Settings exist for power users.

Languages: English, Türkçe.

PERFORMANCE

The capture path is gated by hard CI benchmarks.
• fetch overhead p95: 0.012 ms
• XHR overhead p95: 0.001 ms
• Filter 1000 events: 0.25 ms p95
• Outbound requests: 0

Your browser doesn't notice it's there.

OPEN SOURCE — MIT LICENSED

Every claim about privacy or behaviour is verifiable by reading the source. Issues, feature requests and contributions welcome.

LINKS

Website → https://osmnnl.github.io/hindsight/
GitHub → https://github.com/osmnnl/hindsight
Privacy → https://osmnnl.github.io/hindsight/privacy.html
Issues → https://github.com/osmnnl/hindsight/issues
Releases → https://github.com/osmnnl/hindsight/releases
Changelog → https://github.com/osmnnl/hindsight/blob/main/CHANGELOG.md

OTHER EXTENSIONS BY THE SAME AUTHOR

StorageNinja → https://osmnnl.github.io/StorageNinja/
TestDataHelper → https://osmnnl.github.io/TestDataHelper/