Journal Impact Factor Lookup
Look up journal impact factors using a two-source cascade: bundled CSV cache (~200 common journals) → OpenAlex API (approximate 2-year IF for any journal).
Critical rule: Always use journal_if.py for lookups. Never guess impact factors — they change yearly and vary by edition.
Quick Reference
| User wants... |
Tier |
Command |
| Look up IF of a journal |
read |
python3 journal_if.py lookup "Nature Medicine" |
| Search for a journal |
read |
python3 journal_if.py search "cancer immunology" |
| Process a list of journals |
read |
python3 journal_if.py batch journals.txt |
| Cache-only (no network) |
read |
python3 journal_if.py --offline lookup "Cell" |
| Inspect cache state |
read |
python3 journal_if.py cache status |
| Refresh upstream CSV |
write |
python3 journal_if.py cache update |
| Machine-readable CLI contract |
read |
python3 journal_if.py schema |
| Schema for one subcommand |
read |
python3 journal_if.py schema lookup |
Output format
Stdout is a stable JSON envelope when the CLI is not attached to a terminal
(piped or captured by an agent), and a human-readable view when run on a TTY.
To force a format: --format json|table|human|auto. --json is a back-compat
alias for --format json.
Envelope shape:
- Success:
{ "ok": true, "data": {...}, "meta": { "schema_version", "cli_version", "latency_ms" } }
- Partial success (batch):
{ "ok": "partial", "data": { "succeeded": [...], "failed": [...] }, "meta": {...} }
- Error:
{ "ok": false, "error": { "code", "message", "retryable", ... }, "meta": {...} }
Exit codes
| Code |
Meaning |
0 |
success (including partial success) |
1 |
runtime / upstream error |
2 |
validation / bad input (missing file, bad flag) |
3 |
not found (no journal matched) |
Error codes (inside error.code)
| Code |
Retryable |
Exit |
Meaning |
not_found |
no |
3 |
Lookup completed but no source matched |
upstream_unavailable |
yes |
1 |
OpenAlex API failed transiently; retry later or use --offline |
file_not_found |
no |
2 |
Input file path does not exist |
validation_error |
no |
2 |
Bad argument or flag combination |
runtime_error |
yes |
1 |
Unexpected internal error |
Data Sources
Bundled CSV — ~200 top journals across life sciences, medicine, chemistry, physics, and engineering. Curated from JCR data, shipped with the skill. Always available, instant.
OpenAlex API — Free, open API that computes an approximate 2-year impact factor from citation counts. Covers virtually all academic journals. The number differs from the official JCR IF — it's a citation-rate metric computed from the same formula (citations in year Y to items published in Y-1 and Y-2, divided by citable items in those two years) but using OpenAlex's own article classification. Adequate for ranking and comparison; do not cite as "the JCR impact factor" in formal contexts.
When to use which
| Scenario |
Source |
| Quick check of a major journal |
Bundled CSV (instant) |
| Niche or newer journal |
OpenAlex fallback (automatic) |
| Formal submission / grant |
Note: OpenAlex IF ≠ official JCR IF. Cite only as approximate. |
| Batch processing many journals |
CSV for cached ones, OpenAlex for misses |
| Offline / air-gapped |
--offline flag (bundled CSV only) |
Workflow
Step 1: Detect Intent
| Intent |
Action |
| "What's the IF of Nature?" |
lookup "Nature" |
| "Compare IF of Cell and Science" |
Run lookup twice, compare results |
| "Which immunology journals have IF > 20?" |
search "immunology" then filter |
| "Process this list of journals" |
batch journals.txt |
| "Is this a high-impact journal?" |
lookup then interpret IF in field context |
Step 2: Execute
Run the appropriate journal_if.py command. The script handles:
- Local CSV lookup (instant, ~200 curated journals)
- OpenAlex API fallback (automatic, approximate 2-year IF)
- Fuzzy matching — catches minor name variations
Step 3: Present Results
- Show the journal name, impact factor, and data year
- Note the source (CSV cache vs OpenAlex approximate)
- For search results: show a table with IF, year, and category
Understanding Impact Factor
| IF Range |
Typical Tier |
Example |
| > 30 |
Elite (top 0.1%) |
Nature (64.8), Science (56.9), Cell (64.5) |
| 20–30 |
Exceptional (top 1%) |
Cancer Cell (50.3), Immunity (32.4) |
| 10–20 |
Excellent (top 5%) |
Nature Communications (16.6), Sci Adv (13.6) |
| 5–10 |
Strong (top 15%) |
eLife (7.7), Cell Reports (8.8) |
| 2–5 |
Solid |
PLOS ONE (3.7), Sci Rep (4.6) |
| < 2 |
Niche / new |
Many field-specific and new journals |
Caveats:
- IF varies dramatically by field — a top mathematics journal may have IF < 5 while a mid-tier oncology journal has IF > 10.
- Always compare IF within the same field.
- The IF data year matters; values shift annually.
- OpenAlex approximate IF differs from official JCR IF; treat as a ranking metric, not a certified number.
Batch Processing
Create a text file with one journal name per line:
Nature Medicine
Journal of Biological Chemistry
Proceedings of the National Academy of Sciences
Then run:
python3 journal_if.py batch journals.txt
Troubleshooting
| Issue |
Solution |
| "No data found" |
Try a shorter/alternative name; use search for fuzzy matching |
| OpenAlex returns 0 or None IF |
The journal may be too new (needs 2+ years of data); use --offline to check cache only |
| OpenAlex IF differs from JCR |
Expected — OpenAlex uses its own article classification. Use for ranking, not formal citation. |
| Cache download fails |
Check network; the bundled CSV still works offline |
| Wrong journal matched |
Use more specific name; the fuzzy matcher picks the closest substring match |
1---2name: journal-if3description: Use when looking up journal impact factors (JCR IF), checking a journal's impact factor by name, comparing IF across journals, or answering questions about "影响因子" / "impact factor" / "IF". Triggers on "impact factor", "journal IF", "影响因子", "JCR", "IF score", "journal rank", "which journal has higher IF", "what is the IF of". PROACTIVELY USE when user mentions journal prestige, publication venue quality, or manuscript submission target evaluation.4---5
6# Journal Impact Factor Lookup
7
8Look up journal impact factors using a two-source cascade: bundled CSV cache (~200 common journals) → OpenAlex API (approximate 2-year IF for any journal).
9
10**Critical rule:** Always use `journal_if.py` for lookups. Never guess impact factors — they change yearly and vary by edition.
11
12## Quick Reference
13
14| User wants... | Tier | Command |
15| --------------- | ------ | --------- |
16| Look up IF of a journal | read | `python3 journal_if.py lookup "Nature Medicine"` |
17| Search for a journal | read | `python3 journal_if.py search "cancer immunology"` |
18| Process a list of journals | read | `python3 journal_if.py batch journals.txt` |
19| Cache-only (no network) | read | `python3 journal_if.py --offline lookup "Cell"` |
20| Inspect cache state | read | `python3 journal_if.py cache status` |
21| Refresh upstream CSV | write | `python3 journal_if.py cache update` |
22| Machine-readable CLI contract | read | `python3 journal_if.py schema` |
23| Schema for one subcommand | read | `python3 journal_if.py schema lookup` |
24
25### Output format
26
27Stdout is a stable JSON envelope when the CLI is **not** attached to a terminal
28(piped or captured by an agent), and a human-readable view when run on a TTY.
29To force a format: `--format json|table|human|auto`. `--json` is a back-compat
30alias for `--format json`.
31
32Envelope shape:
33
34- Success: `{ "ok": true, "data": {...}, "meta": { "schema_version", "cli_version", "latency_ms" } }`
35- Partial success (batch): `{ "ok": "partial", "data": { "succeeded": [...], "failed": [...] }, "meta": {...} }`
36- Error: `{ "ok": false, "error": { "code", "message", "retryable", ... }, "meta": {...} }`
37
38### Exit codes
39
40| Code | Meaning |
41|------|---------|
42| `0` | success (including partial success) |
43| `1` | runtime / upstream error |
44| `2` | validation / bad input (missing file, bad flag) |
45| `3` | not found (no journal matched) |
46
47### Error codes (inside `error.code`)
48
49| Code | Retryable | Exit | Meaning |
50| ------ | ----------- | ------ | --------- |
51| `not_found` | no | 3 | Lookup completed but no source matched |
52| `upstream_unavailable` | **yes** | 1 | OpenAlex API failed transiently; retry later or use `--offline` |
53| `file_not_found` | no | 2 | Input file path does not exist |
54| `validation_error` | no | 2 | Bad argument or flag combination |
55| `runtime_error` | yes | 1 | Unexpected internal error |
56
57## Data Sources
58
591. **Bundled CSV** — ~200 top journals across life sciences, medicine, chemistry, physics, and engineering. Curated from JCR data, shipped with the skill. Always available, instant.
60
612. **OpenAlex API** — Free, open API that computes an approximate 2-year impact factor from citation counts. Covers virtually all academic journals. The number **differs from the official JCR IF** — it's a citation-rate metric computed from the same formula (citations in year Y to items published in Y-1 and Y-2, divided by citable items in those two years) but using OpenAlex's own article classification. Adequate for ranking and comparison; do not cite as "the JCR impact factor" in formal contexts.
62
63### When to use which
64
65| Scenario | Source |
66| ---------- | -------- |
67| Quick check of a major journal | Bundled CSV (instant) |
68| Niche or newer journal | OpenAlex fallback (automatic) |
69| Formal submission / grant | Note: OpenAlex IF ≠ official JCR IF. Cite only as approximate. |
70| Batch processing many journals | CSV for cached ones, OpenAlex for misses |
71| Offline / air-gapped | `--offline` flag (bundled CSV only) |
72
73## Workflow
74
75### Step 1: Detect Intent
76
77| Intent | Action |
78| -------- | -------- |
79| "What's the IF of Nature?" | `lookup "Nature"` |
80| "Compare IF of Cell and Science" | Run `lookup` twice, compare results |
81| "Which immunology journals have IF > 20?" | `search "immunology"` then filter |
82| "Process this list of journals" | `batch journals.txt` |
83| "Is this a high-impact journal?" | `lookup` then interpret IF in field context |
84
85### Step 2: Execute
86
87Run the appropriate `journal_if.py` command. The script handles:
88
891. **Local CSV lookup** (instant, ~200 curated journals)
902. **OpenAlex API fallback** (automatic, approximate 2-year IF)
913. **Fuzzy matching** — catches minor name variations
92
93### Step 3: Present Results
94
95- Show the journal name, impact factor, and data year
96- Note the source (CSV cache vs OpenAlex approximate)
97- For search results: show a table with IF, year, and category
98
99## Understanding Impact Factor
100
101| IF Range | Typical Tier | Example |
102| ---------- | ------------- | --------- |
103| > 30 | Elite (top 0.1%) | Nature (64.8), Science (56.9), Cell (64.5) |
104| 20–30 | Exceptional (top 1%) | Cancer Cell (50.3), Immunity (32.4) |
105| 10–20 | Excellent (top 5%) | Nature Communications (16.6), Sci Adv (13.6) |
106| 5–10 | Strong (top 15%) | eLife (7.7), Cell Reports (8.8) |
107| 2–5 | Solid | PLOS ONE (3.7), Sci Rep (4.6) |
108| < 2 | Niche / new | Many field-specific and new journals |
109
110**Caveats:**
111
112- IF varies dramatically by field — a top mathematics journal may have IF < 5 while a mid-tier oncology journal has IF > 10.
113- Always compare IF within the same field.
114- The IF data year matters; values shift annually.
115- OpenAlex approximate IF differs from official JCR IF; treat as a ranking metric, not a certified number.
116
117## Batch Processing
118
119Create a text file with one journal name per line:
120
121```
122Nature Medicine
123Journal of Biological Chemistry
124Proceedings of the National Academy of Sciences
125```
126
127Then run:
128
129```bash
130python3 journal_if.py batch journals.txt
131```
132
133## Troubleshooting
134
135| Issue | Solution |
136| ------- | --------- |
137| "No data found" | Try a shorter/alternative name; use `search` for fuzzy matching |
138| OpenAlex returns 0 or None IF | The journal may be too new (needs 2+ years of data); use `--offline` to check cache only |
139| OpenAlex IF differs from JCR | Expected — OpenAlex uses its own article classification. Use for ranking, not formal citation. |
140| Cache download fails | Check network; the bundled CSV still works offline |
141| Wrong journal matched | Use more specific name; the fuzzy matcher picks the closest substring match |